There´s no one editor can do the things integrated, so you can use Walton´s for livery, and specially gp4 Master to shaping cars.
PS: Please Madman or Lauren can you make a tool that can do all stuff in one.................PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
When the others says you are the best, the worse error is to start to believe it. - Juan Manuel Fangio