Yes, underbody is where its all at, underbody corrosion first mentioned in 2018, only a close examination to decide how bad.
I had a browse the other day, quite surprised how cheap some 120's are being advertised at, a 2 minute browse on the MOT history soon explained, rust rust and more rust.
Notice some ads deliberately avoid showing or actually cover up the reg plate, am i the only one who wouldn't even bother to go look at one that's obviously hiding the MOT history unless it was literally around the corner.