Hey folks, just joined tonight - greetings from Belfast, N.Ireland!. After buying a 2006 A4 (B7) Auto (tiptronic) a few weeks back, have only driven it 4 or 5 times, a few short local trips &  a 100 miler round trip. Was fine until 50 miles into the last drive, I was pulling off the motorway and it ground to a halt on the slip. Was not able to engage D or R, the selector will move into and out of P, R, & N, but wont go into D or S (just bounces back to N). When in R, if I floor it, no matter how high the revs go, it just won't engage at all. The selector will go into tiptronic , but 1,2,3,4,5,6 just flashes on the dash and it doesn't select any gear. No error codes displayed on the dash either. The car will free wheel. Looking at the full service history, the gearbox had an Oil & Filter change at 41K miles in 2011 and then a month later it was into the local Audi garage for a replacement gearbox control unit. No gearbox work in the last 60K miles. Full service history every 10K miles, last service Nov '17. The car is mint, so really hoping I can fix it without breaking the bank. Here's a vid of what I'm experiencing,  

Just wondering if any of you guys have experienced the same? It's probably going to be sent to an 'automatic gear box repair specialist' , but that will be 50 miles away on a recovery truck, would love to find a simpler fix that my local mechanic might be able to try first.

Cheers, keeno 

Reading the past history u included in ur post I would say it's the linkage or the control box rather than the gear box itself failing. Be interesting to find out what it is though.

Welcome to forum BTW!!