I am experiencing the following problem: door lock mechanism on driver's side on my 100 Quattro has stopped working/locking. Insertion and turning of the key activates the alarm, but that's it. I have not yet done anything (e.g., removing door panel, checking linkage, etc.) but wanted to find out if anyone else has experienced this and can give me some guidance. Thanks! Mark 91 100Q 87 5KCSTQ