The first in a long line of hot 5-Series variants, the E12 generation M535i was something special when it first appeared in 1979. Created by installing the 218bhp 635CSi engine into the 5-Series body, the M535i emerged as an astounding Q-car. Deep front spoiler and cross-spoke ally wheels were an immediate give away, but treats for the driver included a ZF gearbox, Recaro seats and a limited slip differential. Most have rusted away (or ended up going off the road backwards), and the remaining cars are cheap considering their all-round ability.
info from Octane