At the risk of really giving myself away here with how little wrenching I've done before.. ......I have a question.. I'm about to buy an air compressor for light wrenching....plus sanding of rust spots... spraying of rust preventatives and light painting and also I want it to be able to take my lug nuts off and on for quick tire removal. So... what size is best for me? I'm researching them all and I see 3 gallon, 15 gallon, 20 gallon,.. etc.. I assume I probaly need 125 PSI And the CFM.. what is the min I need for lug removal? Any useful advice for my first Compressor purchase? (yea, I know.. just take the rig to the freakin dealer) hahahahah thxs..