I have bought and still own some cars that are Cat C & Cat D...Cat C is not much good for resale, but Cat D is only really a decision to label the car as uneconomical to repair but someone has bought it for salvage, repaired whatever damage was there and resold it. Not really a problem as you can get a great car, that has been repaired extremely well (worth checking though) and you can get it for a cracking price but there may be some loss in retail that's worth considering