I developed a practice after having worked at an OEM. I do the following with each new car:
- Open all doors, hood, liftgate/trunk and closely examine all hinges and attachment bolts/hardware for any evidence of replacement, repaint, or asymmetry in the condition of such hardware from one side of the car to the other. If/when a vehicle is damaged post-assembly, repair methods may not be obvious, so look for all subtle signs of any disturbance.
- "Shotgun" the car. This means standing at the right rear, left rear, right front, left front, and from each position standing there for a while, eyeballing alongside the length of the vehicle at the liftgate/fender/and door fits. Look for anything under/overflush, door too high or low, trim alignment. Take your time and let your eyes "pour" over each and every seam and part.
- Go to the sheetmetal seams between doors/hood/rear quarter/liftgate, close your eyes, and run your fingertip along the seam. There should not be variation/undulation of one going higher or lower than the other...they should fit and be flush. Your sense of touch can alert you to look more closely. Seams should be fairly consistent between all panels, as there is a corporate spec for sheetmetal gaps.
- Tell the salesman to give you 10 minutes alone with the car so you are undisturbed.