In my 99.5 Avant next to the cd player is the cell phone jack that everyone talks about for the prewiring, next to that is a coax connector that looks like it might be for a cell phone antenna. I haven't seen this in the Faq's, I have tried searching the boards, but that isn't functional right now. Does anyone have a clue? is there a cell antenna built into the whip on the avants?

Yes, the roof antenna on Avants is a combo radio/cellular antenna. The installation instructions are in a technical service bulletin at tech.vw.com. You'll need Adobe Acrobat Reader to look at them.<ul><li><a href="http://tech.vw.com/audipdf/91-98-06.pdf">A4 Avant Cellular Phone Installtion Instructions</a></li></ul>