need advice on what to do first
 

I have $500 in my "fix up the Buick" fund and its driving me crazy to spend it. the car already has a cold air intake, pitbull chip, Borla exhaust, and 3200 stall. What could I do for 500 that would be a nice upgrade or should I keep saving and do something else....yes I've read the the recipe page....but this will be the first thing I've done to the car everything was done by the first owner....thanks - John