how much you wanna spend??
I'd agree stay away from turbo on the auto, focus on handling, stereo, and style. AVOID RICE!! most P5 owners are pretty good about this; keep it that way!!
Change to poly bushings on the swaybars, or depending on what kind of ride you like, upgrade the struts and springs. You'll need to drop that puppy an inch or so anyway to make it look good on your rims.
Replacing the stock speakers w/decent ones and adding a powered sub is a cheap way to get good sound. Plus keeing the stock hu is a good theft deterrent!
Yank off the roof rack if you like the look, paint the headlights if you like the look (actually i don't), tint helps a lot.
Throw on a decent sri or cai, and if you get an exhaust, GO CUSTOM. it's cheaper, you can get any sound you want, the shop will back up their work, etc etc.
USE THE FORUMS and learn how to use the search function.
HAVE FUN!(guitar)