Make the OWNER drive you around first, before you ever sit in the drivers seat. This way you feel all those odd vibrations, and can actually listen to the engine, to make sure it runs smoothly. Also, if it's a 5spd (which it ought to be) then you can tell if he actually knows how to drive it and just isn't some guy who bought it thinking it "looked cool" and didn't know a single thing about the car. Just my thoughts