when buying a used car always remember your buying someone else problem so make sure you can live with the problem or fix it or prevent a common problem that could happen on specific cars.
If they have modified it at all, expect sloppy, hack, get er done work. Like Shitty wiring causing potential headaches…if there is some kind of motor swap or aftermarket electronics installed ( It makes me barf to see how some people on this forum do wiring). Check for rust on the frame and strut towers. Look around the gas filler neck for rust. Its best to look under the car on a hoist, then you can really get a good view of what your buying. Brake disc and pad condition. Take off the oil fill cap on the rocker cover and have a look inside. If its all black and gunky then its a sign that the owner has not taken care of the engine…it should have a nice clean brown/tan look to it. Take it for a test drive, feel the clutch. If it engages right a the top of the pedal and feels kinda mushy its a good indicator that the clutch will have to be replaced soon or the clutch master cylinder. Stomp in the brakes…does it stop? Do the wheels lock up? Shift up and down through all the gears, do they all go in easy? If not there is a issue with the tranny. Does it have aftermarket suspension parts? Are they a shitty brand like meagan? You may need to replace shit because its worn out and has lots of play. Also just common sense stuff…does it look worn out or broken…it probably is. Hope this helps you out.