BMW M3 Competition (G80) versus Mercedes-AMG C-Class C63 S (W205). 0 points of retained value between them.
The numbers are deceptively equal. Both cars weigh the same, both make 503 bhp, and at 291 bhp per tonne both deliver identical performance density. But the G80 M3 Competition cost £75,000 new against the W205 C63 S's £66,429, which means the AMG bought you the same power for £17 less per horsepower. That gap matters less now than what the used market is actually handing you: a naturally-depreciated 4.0-litre twin-turbo V8 saloon that reviewers consistently describe as one of the last genuinely unhinged AMGs before the brand started managing its character to death. The M3 Competition is the more complete machine, no question. Its inline-six is technically brilliant, the chassis adjustability is exceptional, and it will embarrass faster cars on a wet road. But the G80 is also a car that asks you to accept controversial styling and a personality that, for all its brilliance, leans clinical. It rewards the driver who wants a precision tool. The C63 S rewards the driver who wants an experience. For a used buy today, the C63 S is the smarter choice. It launched cheaper, has had longer to depreciate, and it offers something the M3 simply does not: a thunderous, characterful V8 that makes every journey feel like a minor event. Performance cars at this level are emotional purchases. The AMG earns that emotion honestly, and for less money from the start.