Personally they have a ceiling after which most mods are too expensive bang for the buck wise.....

IF I had one, i'd most likely get...

NVidia Exhaust
AEM CAI
Some kind of header (comptech maybe?)

Amuze front lip
HRE 540's in black
Possible vented carbon hood

WHY? My friend has this exact car minus the header... I borrowed it for almost a week....

Never did I get so many looks in a car (cept my old black 300Z) and have so much fun...

It wasnt the fastest thing out there, but It was sure fun to play with all those revs on the local twisties. It was a car that couldnt hurt u even if you tried! (well maybe not, but I couldnt seem to get it to spin if I drove fairly smart)

Past this all mods get quite expensive, even the header is a stretch and I'd have to look at the prices to see if it was worth it..

Car also had some Intrax springs on it, but I'm not sure how I liked them for handling compared to stock cause it was on stock struts, but it certanily made the car LOOK better and didnt seem to hurt much of anything... I think the increased handling over a perfectly stock car came from the fact that the HRE 540's had 285's on the rear and 255's on the front...