I was going to go matt black but i decided to go gloss, really chuffed how they came out. This is how i done it;
1) Removed the kidneys, its a simple job just two clips.
2) Theres 4clips holding each kidney on, i used a pick to unclip these. There prone to breaking so try and be careful.
3) I abraded the kidneys using a P320 paper.
4) I solvent degreased them to get rid of any contaminents then applied an adhesion promotor.
5) Applied a 2 coats of plastic primer. (1 half, 1 full)
6) Applied a aerosol powder guidecoat, then flatted using a P400. You need to go easy so you get no break-throughs.
7) Solvent degreased once again, the application of colour. 2 coats (1 half, 1 full)

Straight over the top with clear, 2coats. (1 half, 1 full)
9) Then flatted using P2000, just to dull off. Then i polished them, i used a cutting compound then moved onto a finishing polish
10) Then fitted them back to the trim. About 3 clips broke when i was getting them off so i used a little super glue to ensure they werent going no where.
Vintage BMWs are an addiction.