Goal on this one was to be VERY OEM in appearance but outperform what BMW 'would' have offered on the vehicle.
Luckily I had a buddy locally that let me borrow HIS 1-Series for retrofitting...and luckily his car has OEM Projectors with HIDs...so this comparison is the best it could have been.
Basically, the clients car was OEM Halogen bulbs with halogen reflectors (headlights I'm modifying).
Donor car has Bi-Xenon HID Projectors from the Factory.
In order to surpass the quality of Das Engineers over at BMW, I went with the Brand New Bi-Xenon Morimoto D2S v4.0 Projector with OSRAM Xenarc NightBreakers.
Again, key was to keep this OEM....even though the car doesn't have HIDs.
So the install was pretty straight forward...and with the help of the E46 shroud, you'll have a hard time telling if the car came like this or not.
Only thing signifying a non-OEM appearance is the rear access panel.
Due to front lens clearance issues, the resulting problem is the new D2S igniter socket interferes with the access panel closing 100%, which would cause moisture to get into the lights.
So, I removed as much as possible without compromising the structural integrity of the bracing and closing hasps.....and then fabricated my own back plate.
I first secured it to the inside and then heat-formed it to allow internal clearance from the igniter socket. This way minor adjustments can be made once lights are on the car for good.
All in all, this was simple retrofit and the outcome will be sure to impress the owner and anyway riding along!