Just noticed the rt side, low beam headlamp is out on my 2000 Q45. These are the hid lights. Is this going to be an expensive, dealer only, fix or can I head to autozone? I'm expecting expensive. Thanks.

No to Autozone. Call Autobarn or someone like Joe and get the bulb.

Extreme care is required, but it can be DIY with a FSM.

Replacing the hid bulb is just simple like replacing a conventional bulb. Before buying another bulb, you should switch the other bulb in to make sure if that bulb is really bad. Most of the time a fuse is blown or the ballast is bad. If you don't want the high price from the dealer, you could pick up a pair of D2R's from eBay for about $50. Try to search for "D2R" , "85126" or "85126+". I recommend replacing both at the same time for matching colors but if you want to replace just one that is ok, just remember to use the "85126+" for the replacement. The "85126+" is a little more blue compare to new "85126" so it will match the color of an old "85126".

Thanks for the replies. I'm hoping it's a fuse. Bulbs and especially ballasts get pretty salty. Where would the fuse be located?