Take somebody with you.
I think alot of problems on here would be avoided if people buying a car would take an impartial party with them when looking at a car.
First of all, Take somebody that know something about what you are looking at buying. If your buying a dragster take a buddy who has one. If It's a muscle car take a body man or mechanic.
Even if you are experienced take another person. They might see something you missed on the car. Some time people buy with their heart not their brain. OMG this is a '67 Chevelle like I've always wanted!!! I gotta have it!! Then they get it home and find a ton of stuff wrong with the car. Then complain and put up negative post about the seller.
The best person to take with you is one that will pick the car apart. They won't just agree wtih you because you like it.