Have been welding on my own projects (used to do it for Money) for 40 years and Peter is right you dont just pick up a welder wire or stick and get good welds on thin metal.If you plan to do much restoration work on cars a begining welding class at a comunity College will be the best thing you ever did.And DON'T buy an el cheapo wire welder they tangle wire worse than a left handed casting reel.Also look in factory manual before welding on any computerised cars......
William Rogers...... P.S. after 40 years I can weld body panels with a buzz box if thats all there is to work with........