23/05/2026
We continue to get a lot of enquiries about the rear arches on the E46 M3 and it got me thinking about which car had the worst. We’ve seen some from beginning to corrode on the inner arch to the arch actually missing but I think this car was the biggest surprise. The sealer on the inner was clinging on for life and hiding just how bad they were.
I have included a few pictures of different stages of the repairs. There is also a picture of a common area of corrosion lower front rear arch where corrosion starts behind the grommet and spreads behind the sealer. If you remove the grommet and feel the sealer lifting from the metal slightly then it’s begun. Replacement inner arches do not cover this area so it becomes an extra job to do at the same time but it’s a straight forward panel to make and replace.