BMW Z4 Roadster (E85)
Flagged undervalued because asking -13% vs historic sold, and sell-through 86%.
What It's Actually Worth
Blended value of a standard 19 yr, 53k mi example, ~$11.6K 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.
Did our model work? 39% 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 80 scored forecasts: 39% got the direction right, median value error ±41%.
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 7 in 10
We replayed 428 past auctions in this market — predicting each hammer price from market data before the sale (no hindsight). Typical miss: ±28%; the gavel landed inside our predicted range 7 in 10 of the time.
| Sold | Car | Our range | Hammer | |
|---|---|---|---|---|
| 2026-08-06 | 2007 · 32k mi | $9.3K–$20.6K | $13.3K | ✓ |
| 2026-08-05 | 2007 · 31k mi | $9.4K–$20.8K | $15.0K | ✓ |
| 2026-08-05 | 2003 · 111k mi | $5.2K–$11.4K | $5.3K | ✓ |
| 2026-08-04 | 2003 · 2k mi | $11.2K–$24.7K | $17.0K | ✓ |
| 2026-07-30 | 2003 · 30k mi | $9.4K–$20.8K | $8.2K | ✗ |
| 2026-07-23 | 2004 · 30k mi | $9.4K–$20.8K | $13.8K | ✓ |
| 2026-07-22 | 2008 · 111k mi | $5.1K–$11.3K | $22.0K | ✗ |
| 2026-07-20 | 2004 · 51k mi | $7.7K–$17.1K | $8.5K | ✓ |
Live now — calling it before the gavel
We're currently tracking 8 open auctions in this market. Here's our predicted hammer range for each — check back after they close.
| Closes | Car | Source | Our predicted range |
|---|---|---|---|
| open | 2004 | C&B | $6.9K–$19.6K ($11.6K) |
| open | 2004 · 55k mi | hemmings | $6.7K–$19.0K ($11.3K) |
| open | 2005 · 125k mi | BaT | $4.3K–$12.1K ($7.2K) |
| open | 2008 | C&B | $6.9K–$19.5K ($11.6K) |
| open | 2005 | hagerty | $6.9K–$19.5K ($11.6K) |
| open | 2006 · 110k mi | BaT | $4.6K–$13.1K ($7.8K) |
| open | 2004 · 14k mi | classic | $8.5K–$24.0K ($14.3K) |
| open | 2006 · 51k mi | classic | $7.1K–$20.1K ($11.9K) |
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.
Where We Think It's Headed
Probability and range, not a single number. Wider = less certain (not bigger gains).
| Horizon | Direction | Probability | Confidence | Past accuracy |
|---|---|---|---|---|
| 6 mo | UP | 52% | Low | 45% |
| 12 mo | UP | 53% | Low | 39% |
| 24 mo | UP | 55% | Low | 29% |
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 2013
$100K invested 2013-01 → today (13.6 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).
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.
Housing Starts leads by about 10 months (moves with this market, correlation 0.76). Shown shifted forward 10 months so its turns line up with the market's.
Why We Think This
Current Inventory Snapshot
Comparable Markets
| Market | Undervaluation | Appreciation | Liquidity |
|---|---|---|---|
| BMW 1M Coupe (E82) | 17 | 68 | 61 |
| Nissan 350Z | 43 | 68 | 50 |
| Nissan 350Z NISMO | 29 | 55 | 57 |
| Nissan 370Z | 50 | 45 | 50 |
| Alfa Romeo 4C | 54 | 40 | 45 |
| Fiat 500 (2012-2019) | 36 | 58 | 45 |
| Porsche 718 Boxster/Cayman | 44 | 37 | 36 |
| Porsche 718 Boxster/Cayman GT4 | 17 | 38 | 30 |
Recent Signals & Alerts
- vin returned lower VIN relisted $-2,749 vs prior
- vin returned higher VIN relisted +$3,000 vs prior
- vin returned lower VIN relisted $-2,749 vs prior
- vin returned higher VIN relisted +$3,000 vs prior
- vin returned lower VIN relisted $-10,895 vs prior
- vin returned higher VIN relisted +$3,000 vs prior
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.