Firstly, I will only buy used. I have another post where I show what is the best deal.
I think it is very important to do a lot of research on the type of car you are buying. The last thing you want to do is go into buying a car and noting nothing about it. A car salesman isn’t going to tell you all of the downsides to a car. There are many different websites you can go to that tell you all about different models of cars, like: Carfax.com, consumerreports.org
When you are at a car lot (or someone’s house) check all over the car for rust. Rust is a big indicator of how well it has been stored, and if there is a lot of rust underneath, there are probably hidden performance issues.
Take it for a test drive. If you end up buying a car, and you hate the noise it makes then you didn’t do enough research, and either you sell it, or deal with it. You can also tell a lot about the condition of the car by the noise. Remember to check how the shocks feel, If the car is bouncy, and you hit a train track, you could bottom out the car.
Ask lots of questions from the owner.
And here is a funny tip from Car Talk. “Check the radio presets. If it is all hard rock and heavy meddle, it was probably driven hard. If it is all classical and symphonies. It probably never was taken to a bumpy road.”
Those are my main priority when buying a car