I've recently acquired a Crusader tank for my garage:
It is very oppressive and white, and I would like to give it a paint job. However, like many authority vehicles it is apparently "not customizable". I'd leave it at that, if I were not previously able to customize a different kind of "not customizable" vehicle:
I can assure you that the Challenger tank does not usually come in purple, but I can't for the life of me remember just how I managed to get it looking like that. Any advice would be most welcome.