Originally Posted by 777ER
As for the resistors, you need to measure the resistance between the two terminals in the stock headlight housing (disconnected from the car) with a multimeter set to measure a resistance value.
Looking forward to your results with the multimeter 777ER!
As for aftermarket LED's, the guys on the E60 board were having success with 50ohm 10w resistor from Radio Shack. Not sure if that helps since there's the possibility that the OEM LED's have a different resistance.