Hello, my back door has been rusting for years. We also brought the car to the workshop once to remove the rust there, however, it came after 4-6 months again which is quite bad. Because I have now paid for free 210€. Now I tried it myself but somehow I do not know how far I should go. The metal looks quite clean however there are so small cheese holes in it. What should I do with it? Here are some pictures:http://img262.imageshack.us/i mg262/9048/img0046w.jpghttp://img709.imageshack.us/img709/3695/img0045db.jpg What do you want me to do or let it go on? And how do I proceed from now on? I already got rust blockers…