I have a 2007 530xi equipped with stock active xenon headlamps. One of them started going out moments after start up. It sometimes lights again briefly, then goes out. A local BMW completed the usual diagnostics and determined the headlight assembly needs to be replaced due to corrosion of the internal wiring. Is there a good approach for repairing the headlamp assembly? I have read online posts referencing use of electrical tape and liquid insulation. Neither of these approaches is satisfactory. Any other suggestions for repair?