Car appreciation... the aesthetics, the engineering, etc

No experience of buying one but seen plenty of Cat C's and D's through the trade. Unless it's something rare or incredibly cheap I've never seen the appeal of buying something that has been stuck back together. No matter how minor the damage, I can't get it out of my head that it has an insurance classificiation for a reason.

What are you looking to buy?

My two pence on Cat D.
There's no issue with insurance.
Caveat Emptor is the overriding and final advice. But if you can see evidence, photos for instance of the work that's been done (which should be non-structural) and are happy with it, go for it. The only issue will be resale, because it has a stigma.