Things to look out for
Rust is a big killer. Check rear arches, boot lids, and sills where they meet the B-pillar.
Front arches are plastic, so don’t rust, but check for paint damage. If the car has had large wheels fitted, they can come into contact with the inside of the arch, distorting it and cracking the paint.
Electrics are a weak point, so check everything, including the auxiliary instrument gauges, and ensure the electric windows don’t work slowly.
Check for damp in the scuttle cubby on the driver’s side, where the jack is stored. The ECU is in there too, and can be damaged by moisture.