When I bought the car from a garage, there was a small amount of bubbling on the lip of the rear arch. Told them to fix it, and then I would buy the car and they did, just not too well. So some rust appeared and I had a go myself, which looked good and lasted. But I am just seeing it starting to reappear the last few days or so. Seen loads of clio rotting here, and me thinks it is definetly worth keeping on top of, so probably best to do a good job first time round.
If yours has had a a larger knock in this area, which was not brilliantly repaired, then it will probably start rotting severly further down the line. Youd probably best do a proper job, however avoid welding in a new arch if possible as it will be difficult to do well yourself and very pricy at a bodyshop. It depends on how bad the original bang was and how much rust has settled underneath the paint. If its not too bad, try grind all the filler and rust out and redo, just do it throughly and use plenty of zinc primer
Alex M
