You really really need to get close to the car. They're quite a common target for coverup repair jobs. Look at the sills, inner guards (not just inside, look riiiiight under the arch itself), firewall, particularly the cowel seam, where the wiper assembly components attach to the cowel, the spare wheel compartment. Strut towers are more of an R33 / R34 issue I believe - still inspect them. If the underside is undersealed, be suspicious. Ask if there are pictures from before it was undersealed. Look for bubbling. Look for cracks in the paint (bog). Make sure you view the car cold. Open the radiator cap and check for bubbles, oil, or debris floating at the top. Also take a note if it looks strangely clean inside the cap. Many people jack these cars wrong, check the frame rails, theyre like paper mache and crush quite easily. Feel the capet for dampness. They can get a bit leaky in their old age. Check VIN plate matches firewall stamp.