My first thought was 'what's it hiding?'

I used to live back East, and I saw a number of cars that looked cherry outside, but the frame/underside was swiss cheese. One particular low mile '77 Impala I owned briefly the outer body was rust free and looked like it just needed a good buff to look show room fresh.................but the rear axle literally tried to come out of it the frame was so bad.

Prove me wrong, but I'd be very surprised if the underside is as clean as the topside.