72 riviera body check?

I bought a 72 riviera, one of my favorite Buicks, and I wanted to know where to check for weak points on the body and frame.

thx.

 

Up under the rear wheel wells for the frame, the rear quarters on the body, does it have a vinyl top? If so, the whole top and where the trim meets the body.

 

Trunk lids are prone to rust out above the tail lights on 72s.

 

will check

thx a lot