M5 Guru (>2000 posts)
Join Date: Aug 2001
Location: Denver CO
Thanked 80 Times in 65 Posts
Im a sucker for the E28 M5. What can I say, I own two at the moment, and Im looking at acquiring a third, albeit a 1986 Euro Market with the M88/3.
Ive driven the E24 M6, one with a Dinan Stage III Stroker pumping out nearly 400hp and it was a monster in a tuxedo. The looks of the E24 cannot be beat. The E28 is a slightly ugly duckling, but that is part of its attraction to me, much like a Ferrari 412. The E24 is class and it will get attention today.
Lots of M6s out there, not a lot of M5s. So in terms of collectability:
Euro E28 M5
M6/M635CSi (US and Euro, US has a lot of fine fine cars, and they look great, even with the diving board bumpers).
US E28 M5
Im not very up to date on the M6 market, though it seems to carry a premium over the M5. Personally, Ill go for the M5, it just suits me better.