I spent the whole afternoon doing one front cluster on the Vito today, with mixed results. The pre-facelift W639 has a huge light unit that curves in every direction ... not a flat surface in sight. So using the flat sanding disk on it is pretty tricky, even at low rpm. The water involved in wet sanding also made the masking tape come off! Anyway after going carefully through all the grades and lots of polishing I still had fine sanding marks on the surface ... after applying the sealer it looked 'ok' but far from crystal clear. Some 'before' pictures of the washed/dried light:
View attachment 143847
View attachment 143848
And after ... significantly brighter & cleaner (and the bad surface crazing has gone), but not as clear as I'd like:
View attachment 143849
The poor surface is more visible from the side:
View attachment 143850
View attachment 143851
Not sure where to go from here ... I might just try the polish on the other side (which isn't as badly crazed) - the polishing pad is much thicker & softer so easier to use on the curves.