With all this time on my hands I finally replaced the HID bulb that expired and reinstalled my Apexcone Euro style headlights in my M3. I purchased an H1 HID bulb set off of Amazon and as expected they fit great since I had them in for years with no problems. However, the LEDs for the high beams are much longer than the rear cover and require a hole to be made to accommodate the longer bulb body and fan. I tried several solutions to create an environment to protect the lights and fans from dirt and moisture. The challenge I found was there are many solutions for lights with round screw on covers but he odd shape of the E36 headlight rear covers are difficult to fit. I finally found these that have a lip for interior fit and used a 2 inch hole saw on the rear cover to create the needed space for the LED and seal them from the environment. So far everything is working ok and the installation looks neat.

Xtremevision 55mm Rubber Seal Dust Cap Cover for HID LED