Is this the piece you're talking about?
If so, you can have mines. I'll give you the plastic cover too. The one in your picture looks like it's in worst condition than mines? Or it's just dirty? But mines brand new. I couldn't use it cause I lost it lol
That's pretty much all you need. If you're replacing the windshields, you'll need the rubber seals as well. It's like $40 bucks I think. Your body shop probably knows, but I went ahead and bought it myself because I have worked on a few E46s where the seals were the wrong ones or like they used 2 front/rear ones instead of one of each.