I have a vibration somewhere and im not sure whats causing it. I know its not in the engine and that it varies with the speed of the car. At 60mph it happens every 2 seconds in neutral. What parts should i look at to fix this issue?

I am also looking at a t5 and need to know if its plug and play from a sag 4. Clutch, bellhousing, etc.

 

I'd start with tires and wheel balance.

 

So i might as well get new back tires while im at it?

 

Not saying they need to be replaced, but when was the last time they were balanced? VERY common to get one out of balance. Could also be they're just getting old, in which case yeah, get new ones. ....might also be the driveshaft is out of balance. ...I think that's less common, but could certainly cause vibration.

But I think I should've started by asking if you've recently changed/replaced anything. THAT would of course be the starting point.