Windshield sensor for 2004 745i

Greetings all,

I have an issue with my 2004 745i. About a month ago I had the car waxed at a local car wash. Long story short they knocked off the cover that houses the rain and light sensor behind the rearview mirror on the windshield. I didn't realize this until a week later and now I am stuck and no proof that they did the action...

Here is the issue. Directly below the rain and light sensor is another sensor that doesn't have any recognizable part number. This sensor was knocked off the windshield and was somehow damaged. It is held on with a gummy adhesive that you would think would be an easy replace the part and place it back on the windshield. No... BMW tells me I have to replace the entire windshield because that sensor only comes WITH the Windshield. Doesn't anyone have any insight as to how I can get another sensor because I really don't want to pay over a $1000 dollars for a new windshield for something that you would think would cost under 100. As for what this senor does. It appears to tie into my automatic headlights because now they do not turn off when I power the car down.

Sorry this is long but any assistance is appreciated.