BMW M635CSi E24
The BMW M635CSi represented the pinnacle of 1980s grand touring performance. Powered by the legendary S38 3.5-liter straight-six producing 286 horsepower, it combined autobahn-storming capability with luxurious refinement. The E24 6 Series coupe's timeless Paul Bracq styling provided an elegant wrapper for M Division's engineering prowess. With only 5,855 examples built, the M635CSi remains one of BMW M's most desirable classic models.
Values have risen significantly in recent years, with pristine examples reaching $95,000. Verify complete service history especially for the complex S38 engine. Check for rust in battery tray and rear shock towers. Original paint and interior command premium prices. Mechanical fuel injection requires specialized maintenance. Budget $5,000-10,000 annually for proper upkeep.
M635CSi production ran from 1984-1989 with 5,855 units built. European models wore M635CSi badges while US-spec cars were simply M6. The S38 engine was derived from BMW's M1 supercar powerplant.