Problem areas on my car:
Left rear wheel arch "lip" due to an unrepaired scrape. I've just finished stage one of sanding, scraping, Kurusting, filling, sanding, more sanding and such the area to some extent to put it back together, which is about the best I can do with my resources.
Other one is the doors, the inner bottom lip of the passenger one's all but gone, and the driver's one has a couple of holes in. I've got a replacement door for the passenger's side, but not sure what ot do about the other one yet!
Have a lot of surface rust around the battery tray - which has just been thourghly Kurusted as well, the entire underside will be getting treated once the car's MOT'd. Fingers are crossed there's nothing nasty lurking under there.