BMW M5 (E28)
Why 5.5: BMW hand-built the S38 six from M1 stock, dropped it into an otherwise ordinary 5 Series with no wing or wide-body kit, and sold 1,340 to the US for one model year, 1988, at $46,500. A car that traded for used-3-Series money through the 2000s just set a $195,810 auction record, and that kind of run-up moves cars into collections faster than owners can put miles on them.
Layout
Natural habitat
Ride comfort
Market value
Median asking price, good condition · €43k (1988) → €161k (2026), trending up · illustrative data
The long version
BMW Motorsport's engineers took the M1's hand-assembled inline-six, detuned it slightly and dropped it into a 5 Series that looked, from the outside, like someone's company car — no spoiler, no wide arches, just subtler bumpers and a set of BBS wheels giving away what was underneath. That restraint was the whole point: this was the original sleeper sedan, quick enough to embarrass contemporary sports cars while carrying four adults and a trunk full of luggage. The US got exactly one model year, 1988, with a catalyzed 256-hp version of the S38 and a $46,500 sticker, and only 1,340 LHD cars were built for the whole North American run. For two decades that made it a cheap way into hand-built M engineering — clean cars traded for E34-adjacent money well into the 2010s — which meant the ownership base skewed toward people who wanted to drive a piece of M history, not store one. That's changing fast: a 9,800-mile example set a $195,810 record in early 2026, beating the previous record by fifty grand, and prices across the board have followed. The driving enthusiasts are still there, but the newest buyers increasingly aren't planning to find out what the S38 sounds like at redline.