55A is way OTT for thin (car bodywork) welding, so unless you expect to do a lot of thicker welding you've got the wrong machine. With a lot of practice it may be doable, but it will never be ideal. Doubtless someone will come along in a few minutes and claim he can weld cars with a minimum current of 100A, but it's certainly not for the newbie trying to learn MIG welding. It's like trying to split a matchstick lengthways with a tree felling axe. Some people can, but most can't.