Rust on 79 300SD
 

I'm thinking about buying a 79 300SD. Runs well, but has had a cheap paintjob. Where are the popular, but perhaps not obvious, places for these cars to rust, especially where structural integrity is involved? Anything else I should beware of before I purchase?
Thanks!

Rockers, jack points, Floors, bottoms of the front fenders, bottoms of the doors.
Check the rear trailing arms.

I just bought one about 2 weeks ago. I love it! Just the right amount of chrome. Mine has rust in all of the above places except the floors and trailing arms. If these were rusty that would have been a deal killer for me. When I am done restoring my 85 300D, then my 79 SD will be next. I will be repainting everything below the chrome line. The top half is excellent and will be left alone.
You wont be sorry if you get one. They have more get up then the 123, or the 126 cars with the 5cyl turbo. They have a tighter turning radius and seem to out corner the others as well. And as for the looks... Its all about the chrome, and the wood in the interior.

Everywhere. The W116's loved to rust.

Get it up on a lift and poke around.