I would just wack it really hard straight on with a BFH. It should cause enough shock to the threads that it just may allow you to bust it loose. You could heat it up too. Or heat it up, wack it, chalk it, breaker bar and a cheater bar.. I like that combo. Why do you have a bug btw..? Your a jeeper dag-nabbit! You cant have more than one project at a time until your jeep is done.