RD tries to delete all mods that don't follow the policy that all mods have to be made from scratch or has the permission from the original creator.
As far as my knowledge goes. Editing content and uploading it somewhere is infringing "artistic" copyright.
Also a mod that has copyright protected content in it needs to be for free, since you need a license to sell something with a Ferrari logo on it for example.
The community here is very fair and nice. If we see a mod that goes against the rules, it will be reported and then be checked by the RD team.
So you can find a lot of bad mods out there. Most car mods that you can't find here are just a new chassis put on an existing original ac car.
Meanwhile the car mods here on RD all have their own suspension geometry, physics etc.
If you want quality and legal mods. RD is the place to download mods.
If you don't care for either of these and just want your favorite car visually slapped on a wrong car, then there are other sites that have plenty to choose from...