I bought this 02 gt a few months back from a small town dealer. He didn’t know much about the car but I did see it had some mods and drove nicely around the block. Anyway, recently I’ve been spending more time and money on it and have noticed something annoying. Driving, especially over 50 mph, it likes to wander almost dart from one side to another randomly. It might continuously pull one way then the other or it’ll go straight for a while. It’s worse at highway speeds. And when the road surface is uneven it’ll wander even more. The front end is nice and tight, no slip in the wheel at all. So I’m suspecting maybe it’s the rear end. The rear suspension appears to be somewhat new, though that doesn’t mean nothing is bad. Any suggestions? I live in an apartment so space to work is limited.