Since buying my 1983 300D in Nov '08, I've picked up a couple things over the winter:
Chrome cowl vents
16" Ronal R9's
French Style Euros
W123 Mud flap set (latch on, not drill and screw)
Now I just have to wait until it warms up to get working on installing this stuff. Still need a new stereo and speakers, wood shift knob, wood or sport steering wheel, euro bumpers, and some Cibie Oscar rally lights. Add that to the already tinted windows and I think I'll be done. Unless I run into some lowering springs, I think. Or maybe a lift kit!
If you suck at actual mechanical upgrades that actually benefit performance, you might as well look really good driving around clueless.
