Had some time over the weekend to restore my E30 grilles / grills.   Obviously I could've replaced with new, but these ones looked ok and I had some time so why not give restoring a go. Things you need: 1) E30 Grille 2) Plastic Doctor 3) Sponge Seal as shown 4) Oomph   Instructions: 1) Cut the existing foam off with a razor blade 2) Spray residue with Oomph and leave for 2 mins.  Then rub / scrape off. Repeat as necessary. 3) Wash the grilles with det