For performance: There is a supercharger kit available for these cars. Or you can build a turbo system.
Looks: needs more low. At least 2 inches lower. Ditch the wheels, they're very ricer. Check out some diamond racing steelies, or maybe some low offset bbs. Chrome has to go. Door handles body color. Grill and headlight trim satin black.
Do something with the front. Matbe an aftermarket lip or chin spoilers?
Darker window tint (15-25%)
Then of course a good exhaust.
Wire tuck in the engine bay.
New front seats.
That should be a nice car.