((((((URME))))))
I know this is difficult for you. This is your BF's karma not yours. I do not know what a VOP is but obviously he did not take care of it. He maybe out by Monday morning if this is something non violent and there was no victim involved.
If you feel like you can go get his car it would probably save him some money but if you feel you are doing the right thing by not getting it then don't look back on your decision.
Addiction is complicated on both sides. Consequences happen on both sides of the issue.
If you feel you need to detach from him than do the best you can and just be gentle with yourself.