I'd never heard of a Cat C car until I bought one on Sunday! in brief:
Cat C refers to an insurance write off. There are four levels of damage A-D. Cat D = minor and Cat A = virtually impossible to repair.
The car has been involved in an accident and deemed un-economical to repair by the insurance company. The owner then buys back the car off the insurance company and repairs it, re-registers it and sells it on.
I bought the car in good faith, and stupidly didn't do an HPI check, (checks the history of the car eg stolen, damaged etc) until I parted with my money. Transpires that the insurance co refuse to ensure until I obtain a full engineers report, which I'm currently in the process of doing.
Hoping someone out there may be knowledgeable on insurance matters in these cases.