[painthuffer]

You're going to have to grind back the paint around the rust until you find healthy metal.Then you're going to have to use a cut off wheel and cut the rusted area out and replace it with some fresh sheetmetal.While installing the new metal take the time to seal it up good from the elements,because, the one good thing is that now you know where you're problem areas are.If you don't have the proper tools to perform such a fix then you might have to look into replacing the panels affected,or talk to your local bodyshop about getting it fixed.However, knowing bodyshops,they'll most likely replace the affected panels as well.