I used an aerosol can lid. Found a can of paint at work with a lid just the right size. Looking at it it's about the same size as my shaving foam can lid.
yea loads of space in a passat engine bay, fitted fine behind the normal headlights, but had to trim the end of one of the adjusters on the Hellas cos the projector dip beams are so damn deep
Well I finally got around to pulling the hot air hose off the manifold and for the time being it has been rotated 180 degrees and sits above the alternator. I'll get around to finguring something out at xmas. It must be my imagination but I'm pretty sure the car feels noticably better when giving her the boot! (Measured my inelt temps last month and they were as high as 50 degrees C!)