#1 thing to do with any car, especially the e34 is to lower it. you can do all else but the car will look gay unless it's been dropped

having said that.. #1 would be stereo
#2 wheels
#3 exhaust
#4 eat
#5 change all the lights:
eyes (with eyebrows to make them real eyes and not weird circles)
clear corners/sides/rears
#5