Blended value of a standard 37 yr, 9k mi example, ~$155K now. The green line weighs confirmed auction sales most heavily (the amber dots — what cars actually hammered for), blends in fast-selling "just-missed" listings, and lightly smooths out month-to-month composition noise.

━ blended true value ● confirmed auction sales (dot size = volume)

◫ 96 confirmed sales·150 months tracked·since 2014-01·3 active listings

Did our model work? 83% direction calls right

Each faint amber line is a forecast we would have made at that point in the past (12-mo horizon), drawn against what actually happened (blue). Over 6 scored forecasts: 83% got the direction right, median value error ±57%.

━ actual ╱ past predictions (ghosts)

Walk-forward: each ghost uses only data available at that date — no hindsight. Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.

Auction Scorecard gavel in range 9 in 10

We replayed 39 past auctions in this market — predicting each hammer price from market data before the sale (no hindsight). Typical miss: ±16%; the gavel landed inside our predicted range 9 in 10 of the time, and we lean slightly low on average.

Sold	Car	Our range	Hammer
2025-08-16	1987 · 28k mi	$75.4K–$221K	$157K	✓
2025-08-07	1987 · 3k mi	$92.7K–$272K	$205K	✓
2025-05-29	1987 · 55k mi	$63.4K–$186K	$140K	✓
2025-05-12	1987 · 2k mi	$92.0K–$270K	$230K	✓
2025-01-30	1987 · 82k mi	$54.0K–$159K	$102K	✓
2024-10-23	1987 · 19k mi	$73.3K–$215K	$133K	✓
2024-09-07	1987 · 13k mi	$76.0K–$223K	$130K	✓
2024-07-27	1987 · 15k mi	$77.7K–$228K	$100K	✓

No-lookahead: predictions are made before each auction closes; the scorecard grades confirmed sold auctions only (no-sales excluded). A modeled estimate, not a guarantee. Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.

If You’d Bought in 2014

$100K invested 2014-01 → today (12.4 yrs), this car vs where else you could've put the money. Rebased to 100 at the start; the dashed line is inflation (break-even).

━ This car $172K━ S&P 500 $528K━ Gold $366K━ Luxury $559K━ Housing $207K

Solid store of value, but lagged the stock market. The Buick Grand National/GNX GNX roughly 1.7×'d your money (a real, inflation-adjusted 1.2× gain). It LAGGED the stock market by about 67% — the same money in the S&P 500 would be larger. It trailed housing (-17%). (Price only — a real round-trip also loses ~10–20% to buy/sell fees and carrying costs.)

What This Market Follows

Specialty-car prices don't move in a vacuum. These economic indicators have historically led this market — tap one to see it shifted forward by its lead time, overlaid on the value line.

Nonfarm Payrolls (jobs) leads by about 13 months (moves against this market, correlation 0.93). Shown shifted forward 13 months so its turns line up with the market's.

━ Buick Grand National/GNX GNX ┄ Nonfarm Payrolls (jobs), shifted +13mo

Why We Think This

sell-through 75% sell through rate

-47% vs 2-yr avg pct vs trailing 24mo

sale prices -5.7%/mo median sale trend slope

-17% vs 12-mo avg pct vs trailing 12mo

Current Inventory Snapshot

Active priced listings3

Median fair value$151,055

Avg deal score61/100

Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.