Look around the usual spots for rust, front and rear sill ends. Rear wheel arches, the chasis area in the rear wheel. At the back of the car
the corner areas of car. Under the front floor areas, look for plenty of history, service , bills etc. It took me a while to find mine and I viewed a few nails along the way. You know the type of advert immaculate or excellent condition, these terms need to be a bit more defined a little more truthful.

Hopefully a few more knowledgeable people will come along with a few more tips. Don't be put off there are great cars if you pick the right one. All the best in your search.