Used Car Decoder Skill
A used-car listing is a document written by someone who knows the car's
problems, for someone who doesn't. The dialect is learnable: "selling for a
friend" (distance from liability), "drives well for its age" (adjusted
expectations), "minor cosmetic damage" (photographed from the good side),
"no test drives without deposit" (walk away now). This skill decodes the
ad the way [[lease-decoder]] reads a lease — severity-ranked, money math
attached — then arms the viewing: the checks a non-mechanic can actually
do, the questions that surface evasion, and the honest boundary: which
findings mean pay a professional for an inspection and which mean leave.
What This Skill Produces
- A listing decode: phrase-by-phrase, 🔴🟡🟢, with what each hedge
typically means and the question that tests it
- The before-you-travel checks: history/title verification items
(accident/write-off status, finance owing, mileage consistency, recalls)
— each flagged as country-specific-verify-locally with what to search,
since registries differ everywhere
- A viewing & test-drive checklist ordered by cost-of-miss: the
cold-start, the panel-gap walk, fluids, tires including the spare-match,
electronics sweep, the specific listen-fors on the drive
- Seller questions that make evasion visible ("why selling?", "what
would you fix next?", "can I take it for a pre-purchase inspection?" —
the last one is the real test: honest sellers say yes)
- The money frame: comps from sold prices, what each found flaw is
worth in negotiation, and the walk-away list where no price is right
Required Inputs
Ask for (if not already provided):
- The listing text and photos described, plus price and the car
(make/model/year/mileage)
- The buyer: first car or fifteenth, mechanical comfort level, who else
might inspect with them
- Budget truth: the price ceiling including the first-year surprises
buffer (insurance, immediate maintenance)
- Country — for the verify-local flags on history checks and paperwork
(this skill never asserts registry procedures)
Framework
- Decode the ad's dialect. Flag the classic hedges: liability
distance ("for a friend/relative") · condition adjectives doing heavy
lifting ("well for its age", "usual marks") · photo tells (no
full-front shot, wet-car photos hiding paint, interior only) ·
urgency pressure ("first to see will buy") · the deposit-before-
viewing 🔴s. Each flag gets its test question, not just suspicion.
- Never travel before the paper checks. Mileage across ads/photos
consistent? History check run (accident, write-off category,
outstanding finance — finance owing can follow the CAR, not the
seller, in many places: 🔴 verify locally)? Recalls outstanding?
Seller matches the registered keeper? All flagged with what-to-search
terms, none asserted as universal procedure.
- Inspect in cost-of-miss order. Ask for a cold start (pre-warmed
engines are a tell) → head-gasket-adjacent signs (mayonnaise under
the oil cap, white smoke — described plainly for a novice) → panel
gaps and paint-tone walk (accident repair) → tires including
date-codes and the spare (uneven wear = alignment or worse) →
electronics sweep (every window, warning-light theater: which lights
come on at ignition and go off) → the drive: straight-line braking,
full-lock turns, a listen with the radio OFF.
- Let the questions do the work. The pre-purchase-inspection ask is
the sorting hat: "can my mechanic look at it?" — yes means proceed,
any version of no means the listing decoded itself. "What would you
fix next?" beats "any problems?" — everyone answers the second with
"nothing."
- Frame the money before the feelings. Sold-price comps (not asking
prices) set the anchor; each finding gets its rough repair-cost class
(small/medium/engine-money — classes, not fake precise quotes) as
negotiation material. The walk-away list is absolute: finance owing
unresolved, write-off category undisclosed, no-inspection sellers,
mileage that doesn't add up. And the standing rule: the deposit
buffer for year-one surprises is part of the budget, not optional.
Output Format
## Listing decode
| Phrase / tell | Reading | 🔴🟡🟢 | Test question |
## Before you travel (verify-local items)
[ ] History check (search: …) [ ] Finance owing [ ] Mileage consistency
[ ] Recalls [ ] Seller = keeper — each with country-flag
## At the viewing (cost-of-miss order)
[The checklist with novice-friendly descriptions of each sign]
## Ask the seller
[The questions + what evasive answers look like]
## The money frame
[Comp anchor · findings → negotiation classes · the walk-away list ·
the year-one buffer line]
⚠ A pre-purchase inspection by a mechanic beats every checklist here for
engine/transmission health — budget for one on any car you're serious about.
Quality Checks
Anti-Patterns
Related
[[mechanic-quote-decoder]] for after you own it; [[car-lease-decoder]]
for the leasing route; [[car-tco]] for what this car really costs per
year; [[franklin-decision-ledger]] when it's down to two cars.
1---2name: used-car-decoder3description: Decode a used-car listing before you drive an hour to see it — what the seller's phrasing is hiding, the history-check items that matter, a test-drive and inspection checklist ordered by cost-of-miss, the questions that make evasive sellers visible, and the walk-away signs ranked 🔴🟡🟢. Use when someone says 'is this car listing legit', 'what should I check on a used car', 'decode this ad', or is about to buy their first car. Produces a listing decode, the viewing checklist, and the negotiation frame. Not a mechanic — and it says which checks need one.4---5
6# Used Car Decoder Skill
7
8A used-car listing is a document written by someone who knows the car's
9problems, for someone who doesn't. The dialect is learnable: "selling for a
10friend" (distance from liability), "drives well for its age" (adjusted
11expectations), "minor cosmetic damage" (photographed from the good side),
12"no test drives without deposit" (walk away now). This skill decodes the
13ad the way [[lease-decoder]] reads a lease — severity-ranked, money math
14attached — then arms the viewing: the checks a non-mechanic can actually
15do, the questions that surface evasion, and the honest boundary: which
16findings mean *pay a professional for an inspection* and which mean leave.
17
18## What This Skill Produces
19
20- A **listing decode**: phrase-by-phrase, 🔴🟡🟢, with what each hedge
21 typically means and the question that tests it
22- The **before-you-travel checks**: history/title verification items
23 (accident/write-off status, finance owing, mileage consistency, recalls)
24 — each flagged as country-specific-verify-locally with what to search,
25 since registries differ everywhere
26- A **viewing & test-drive checklist** ordered by cost-of-miss: the
27 cold-start, the panel-gap walk, fluids, tires including the spare-match,
28 electronics sweep, the specific listen-fors on the drive
29- **Seller questions** that make evasion visible ("why selling?", "what
30 would you fix next?", "can I take it for a pre-purchase inspection?" —
31 the last one is the real test: honest sellers say yes)
32- The **money frame**: comps from sold prices, what each found flaw is
33 worth in negotiation, and the walk-away list where no price is right
34
35## Required Inputs
36
37Ask for (if not already provided):
38- The listing text and photos described, plus price and the car
39 (make/model/year/mileage)
40- The buyer: first car or fifteenth, mechanical comfort level, who else
41 might inspect with them
42- Budget truth: the price ceiling *including* the first-year surprises
43 buffer (insurance, immediate maintenance)
44- Country — for the verify-local flags on history checks and paperwork
45 (this skill never asserts registry procedures)
46
47## Framework
48
491. **Decode the ad's dialect.** Flag the classic hedges: liability
50 distance ("for a friend/relative") · condition adjectives doing heavy
51 lifting ("well for its age", "usual marks") · photo tells (no
52 full-front shot, wet-car photos hiding paint, interior only) ·
53 urgency pressure ("first to see will buy") · the deposit-before-
54 viewing 🔴s. Each flag gets its test question, not just suspicion.
552. **Never travel before the paper checks.** Mileage across ads/photos
56 consistent? History check run (accident, write-off category,
57 outstanding finance — finance owing can follow the CAR, not the
58 seller, in many places: 🔴 verify locally)? Recalls outstanding?
59 Seller matches the registered keeper? All flagged with what-to-search
60 terms, none asserted as universal procedure.
613. **Inspect in cost-of-miss order.** Ask for a *cold* start (pre-warmed
62 engines are a tell) → head-gasket-adjacent signs (mayonnaise under
63 the oil cap, white smoke — described plainly for a novice) → panel
64 gaps and paint-tone walk (accident repair) → tires including
65 date-codes and the spare (uneven wear = alignment or worse) →
66 electronics sweep (every window, warning-light theater: which lights
67 come on at ignition and *go off*) → the drive: straight-line braking,
68 full-lock turns, a listen with the radio OFF.
694. **Let the questions do the work.** The pre-purchase-inspection ask is
70 the sorting hat: "can my mechanic look at it?" — yes means proceed,
71 any version of no means the listing decoded itself. "What would you
72 fix next?" beats "any problems?" — everyone answers the second with
73 "nothing."
745. **Frame the money before the feelings.** Sold-price comps (not asking
75 prices) set the anchor; each finding gets its rough repair-cost class
76 (small/medium/engine-money — classes, not fake precise quotes) as
77 negotiation material. The walk-away list is absolute: finance owing
78 unresolved, write-off category undisclosed, no-inspection sellers,
79 mileage that doesn't add up. And the standing rule: the deposit
80 buffer for year-one surprises is part of the budget, not optional.
81
82## Output Format
83
84```
85## Listing decode
86| Phrase / tell | Reading | 🔴🟡🟢 | Test question |
87
88## Before you travel (verify-local items)
89[ ] History check (search: …) [ ] Finance owing [ ] Mileage consistency
90[ ] Recalls [ ] Seller = keeper — each with country-flag
91
92## At the viewing (cost-of-miss order)
93[The checklist with novice-friendly descriptions of each sign]
94
95## Ask the seller
96[The questions + what evasive answers look like]
97
98## The money frame
99[Comp anchor · findings → negotiation classes · the walk-away list ·
100the year-one buffer line]
101
102⚠ A pre-purchase inspection by a mechanic beats every checklist here for
103engine/transmission health — budget for one on any car you're serious about.
104```
105
106## Quality Checks
107
108- [ ] Every decoded phrase quotes the actual listing — no generic
109 suspicion without a receipt
110- [ ] All registry/history/paperwork items carry verify-local flags with
111 search terms, never asserted procedure
112- [ ] The checklist is executable by the stated mechanical comfort level;
113 pro-inspection items say so
114- [ ] Repair costs appear as classes, never invented precise quotes
115- [ ] The walk-away list is present and absolute — items where
116 negotiation is explicitly the wrong response
117
118## Anti-Patterns
119
120- [ ] Do not diagnose remotely — signs and their severity class, yes;
121 "that's definitely the clutch," no
122- [ ] Do not assert country procedures (title transfer, history
123 registers, deposit law) — flag and route
124- [ ] Do not let a good price override the walk-away list anywhere in
125 the framing
126- [ ] Do not write the seller as an enemy — most are honest; the decode
127 exists to identify which kind is across the table
128- [ ] Do not skip the pre-purchase-inspection recommendation because the
129 buyer is excited
130
131## Related
132
133[[mechanic-quote-decoder]] for after you own it; [[car-lease-decoder]]
134for the leasing route; [[car-tco]] for what this car really costs per
135year; [[franklin-decision-ledger]] when it's down to two cars.