Apparently the rear left trailing arm on my E46 is bent (the wheel alignment is off and can't be adjusted to fit into specs). So I bought a used one, but there was a problem. Because of the harsh weather, salt and stuff, it was slightly rusty. So I decided to restore it a bit. I went at it with a wire brush, but it was no go, so I sandblasted it myself (looks decent enough for me). I haven't painted it yet, but it is coated with black primer and ready for paint. Still need to change the bushings on it.