I just picked up a 98 GT vert. I don't know any history on the car. What I do know is it is super clean and low miles. It is my guess this was someones weekend toy not a daily driver. As for mods I'm pretty sure it has a cat back setup. The exhaust note is too loud and too mellow for the stock exhaust setup. I have not been able to locate a name or logo on the exhaust, but the mufflers are very "square" vs. the typical oval shape it that tells anyone anything. There is also a cold air intake on the car and a few chrome bits under the hood as well as some stainless braided hoses. All this brings me to cams. The idle is a little rough...a very slight lope at normal 500-600 RPM idle. It's not as noticeable on a cold start-up, but the computer bumps the idle closer to 1000 RPM when cold so it's hard to say for sure. If I pulled up beside this car I would guess it to have a very mild performance cam in it (or cams as the case my be). There is no indication of anything else causing a rough idle...no stalling, hesitation, etc. So, anyone have any thoughts? How the heck would you tell if aftermarket cams had been installed? Even if I pulled the valve covers I doubt I would be able to tell.