first thing you do is to start with the body make sure it is the factory paint, if it is not there is big chance that the car had an accident before or it was affected by corrosion or the car owner just needed to repaint it to make it brighter.
this kind of an accident is hard to repair if it is repaired it is not prefect 100%,
the main parts of car is in the front ,the engine radiator ,and also the steering system it is very dangerous to drive a car with bad steering system..
open the doors and close them check if the close without resistance and hear also the sound while closing
Check the windshield for cracks, chips, scratches and other damage. If they are large enough, they can cause the vehicle to fail a safety inspection and the windshield is quite expensive to replace.
Electrical features
Check all the electrical accessories. Test operation of power windows locks and other features. If the seats are heated try test them, try the power seat adjustments. Test all remote control functions. Try the stereo functions. A CD-player often has some problems and it's quite expensive to fix; try if it plays your CD
Check the engine
Start the engine and keep it running for long time and notice the sound of it ,it should be steady ,press the accelerator every 5 minutes and make somebody
Notice the exhaust ,if its color is black or bluish white, then the engine is bad and don't buy the car ,if you see some water vapor is ok
Turn on the AC without moving the car and see t effect of that on engine temperature
Park the car on horizontal surface while doing this
Sit in the car and see if one of its sides higher than the other and move with the car slowly
let somebody check if it is balanced to avoid chassis defect.
Don't buy high-mileage cars. I'd recommend to avoid cars with more than (145,000 - 150,000) miles.
Test drive the car
Driving the car gives accurate results and you have higher chances to discover possible problems, test the car on different situations and different types of roads, accelerate ,decelerate, stop the car to test the brakes .if you feel any indication of possible engine problem like: vibrations ,delay during acceleration ,smoke ,etc. avoid buying this car.