Does anyone know where I can buy this? (see attachment)

Recently my sunroof stopped working and would only tilt up and down. So I pulled it out of my car and there are some plastic tabs that are apart of the track that have snapped off that seem to be the problem. But the problem is I have to open up the track to replace the plastic piece.

so now the track can't pull the glass into it's final resting position and it is causing my sunroof leak. darn cheap plastic!

Can the dealership or and auto body shop fix this? or can I buy the carriage set separately? Thank you!

 

found the problem here is a diagram that my husband quickly made up... unfortunately you have to take apart the track to fix this which is impossible without some heavy duty stuff =)