Rear Glass Black Molding Paint question?

I just performed this task on my 550. I used Sema semi gloss black paint, which can be sourced from any auto body shop, it comes in a spray can. The rest of it is just prep, more prep. mask and spray...

 

The trim mouldings are aluminium and, as usual, the prep for paint is poor. Mine had corrosion in several places. Repair sequence was:

Mask; fineline tape, then the usual blue masking tape, lots of paper and old sheets, cover the whole car.
Sand; I sanded off most of the original paint - carefully!
Prep the bare metal - Alumiprep or Alodine, brushed then washed with clean water.
Prepsol wash
Prime, normal 2 pack auto primer, well thinned - beige colour, already had some
Spot fill corrosion pits
Carefully sand, feathering the edge next to the tape.
Prepsol, then thinned primer again
Very light sand, 800 W&D, lubricated with prepsol
Paint - 2pack satin/matt wet on wet lightly. I have a buddy in the auto paint business who mixed the correct amount of matting agent to get the right gloss level
All painting done with an Iwata air brush.

Looks original to me and is much more durable than the original.

Completely OTT, but fun.

Took me a week, 30 minutes per day - I like to let the primer cure overnight before sanding, topcoating.