I think it's faulty BALLAST, no need for new headlamp units!

[GS450hSE]

Thumping has no effect at all, whether the light is on (which it is 99% of the time) or being annoying and off.

2008 GS450h (RHD UK) 50K miles and otherwise trouble-free; no local corrosion or similar.

I think it's just faulty BALLAST, no need for replacement headlamp unit.

Someone on another forum suggested it might be wise to first examine the relevant earthing point, if only to eliminate that. Anyone knows where it is located in an RHD car where it is the passenger side HID light that's misbehaving?