My front drivers side seat belt no longer retracts all of the way. It still retracts far enough that it works, but it is getting worse.

Is there a fix for this other than replacement?

If I need to replace it, where is a good place to find a new assembly? FYI: I have the shop manual on CD.

I have searched on the net and have found only "generic" seat belts. Unless I can be assured these will work properly, where can I find an "Audi" belt?

Thanks