Search realoem.com, there may well be options...including my fix, which was $28 to fix what dealer wanted $1500 for...that was 15 years ago for my E36.
Many diys here on fixing sunroofs, realoem will show you parts explosion...you can order parts and drive to get them on sunny day or have them delivered to you...but opening up sunroof isn't so bad at all...but very worthwhile!
You have options...but will need to study up is all.
I'm so depressed. No one wants to come see me. :(
Mangofy your E46!