When looking for cars under 1000 in local adverts, i was finding 5 of every 6 on sale were dealers selling from home. Many had been poorly repaired and the seller did not have his name in the document. There is a lot of rubbish out there.
One Honda Jazz, i was able to contact the previous owner who told me the car had a T bone into one side. The centre pillar went inwards about 6 inches and side airbags went off. The roof was creased. The seller had told me it had a small scratch and dent on the doors and he just replaced the 2 doors. Always look for the airbag light coming on when you turn the key. Often the seller will have cut out the airbag and taken the lamp out. The bumped ones are very easy to spot. Spray under the car, on the door rubbers, around the underside of the filler cap. You can usually feel a part spray just running fingers along the paint but the eyes are your best judge.