I've installed grill mesh on the passenger side vents on my Caysman, and two other Caymans. I cut out two grill sections, upper and lower, for attachment to the painted exterior vent grill piece. As you have found, these two pieces must lay on the painted vent grill piece, but not interfer with the black plastic framing piece. From the local hobby shop, I purchased a few pieces of brass, rectangular box-section rectangular stock that measures 1/2 inch by 3/16 inch, by whatever length it came in--something like 8 or 10 inches. I cut these into 1 inch long pieces, and drilled a 1/8 inch hole clear thru both of the 1/2 inch sides. After scraping away some paint (I used a Dremel tool) six of the brass pieces are glued ( using 5- minute epoxy) into the painted vent grill piece-- two for the top and four for the bottom grill mesh pieces. You need to position the grill mesh pieces on the painted vent grill piece so you will know where to position the brass --you will be using screwing sheet metal screws into the holes in the brass, so you need to line-up some openings in the grill mesh with the holes in the brass pieces. Mark the positions, then glue in the brass pieces. Wait one hour for the epoxy to fully cure, the screw the grill mesh to the painted vent grill using the appropriate size sheet metal screws and washers. Assemble the painted vent grill to the black frame, then pop the whole assenbly back into your car. I have also made and installed grill mesh on the front of the car-- all three openings--and the rear diffusser openings. You might say I'm "all meshed up". I will try to get some new photos of my car today that shows the front, side and rear grill mesh.