Hi, just bought my daughter a 107(2006) sadly didn't notice rust on the sill on the passenger side , mainly underneath, just lipping around the side. There is also a thin band of bubbles along the bottom of the door. I took it to a body shop who say it's been badly repaired at some point, thus causing these issues. Wondered the best way to try and deal with myself to prevent it getting worse. I was thinking of rubbing down the sill and treating with rust agent, then spraying with a stone chip shield ? Not sure about tackling the door as some bubbles are going up the hinge side edge.....any advise , techniques, products etc to use would be appreciated...thanks for reading ?