I have some brightness issues with my HUD (cannot see it in normal daylight!) and suspect that the dealer replaced the windscreen with a non-HUD one before selling the car (bought a used Premium Selection). How can I check that? I was looking for the windscreen part number but only found the Splintex and BMW logos and the 43R-000049 number on the lower right side of the screen. Thanks for the help!

2007 E60 540i

It is possible the dealer had the glass replaced with conventional glazing - you're correct that the HUD requires a special windscreen. I checked http://www.realoem.com/bmw/ but that part number doesn't match any glazing number. I also googled ( 43R-000049 BMW ) it and a post in german referenced glass with that number but no additional detail.

The brightness of the HUD can be adjusted in iDrive - try that. If it doesn't work, I suggest you call the dealer and ask that they examine the windshield and if necessary replace it with the correct glazing or fix the HUD if it isn't working properly .