Interesting topic. Not sure what the score is for Mercedes but bulbs were never covered at other manufacturers i have worked for. Will have a check.
I have XENON lights in my car and i love them. But then i wouldnt have to pay for them to be replaced which as everyone else has found, costs a lot.
My vans have now moved on to full LED systems. Havent even seen them on cars yet so its going to be interesting. Not just those posing DRL’s people have. These have LED’s on all lights which alter light pattern, dip automatically, follow the road, change to LHD automatically etc etc etc. TBH i am not pushing them, at £1400 it seems to be a way of reinventing something that wasnt broken.