1986 BMW 528e Help

Im looking at getting a BMW 528e (1986) and was wondering if there is much in the way of upgrades sucha as;
-Exhaust
-Intake
-ECM
-Coilover set up
-Braces

Im not trying to make it a vett killer or anything just quick with a good exhaust note.

I know there are quicker bimmers out there but, I like the body styles these cars have, I am very mechanincally inclined and if later on, wanted more power may add a turbo, or supercharger, or a bigger engine outta a newer bimmer, your help is appreciated!

-Dudz