It seems to be a common problem on B7 Avants that the design of the rear wiper motor lends it self to failing. Mine decided to fail and upon checking it, I found that it had seemingly been leaking washer fluid into and around the wiper motor which played havoc with it resulting in its failure.
Seeing as its a common fault I decided to do a little how to guide whilst doing mine as its a very simple job to do and you could save yourself a few £ by doing it yourself rather than paying a dealer. The part cost me £80plus the vat.
10mm socket, or 10mm spanner
T15 torx bit
First job is to remove the wiper itself
pull off the plastic housing, the jets usually come off with this, mine did.
remove the 13mm nut from the wiper spindle
then remove the wiper arm - I just flexed it a bit with the wiper arm is the raised position and it came off very easily
now to the inside.
lift the tailgate, and open the warning triangle compartment and remove the triangle. There are two T15 torx bolts in there - undo these. In the picture you can see the hole in the top right of the picture.
In the handgrab holes on either side there are two more screws to remove - for some reason these were Philips on mine and not Torx like the centre ones.
You can now pull the trim downwards - there are some clips to overcome to expect to use some force. Pull it down enough so that you can get your hand in.
With them trim down you can now see the wiper motor. You can see on mine how its been leaking and this has gone all over the motor and the multiplug connector.
remove the multiplug connector by pulling it.
then remove the washer feed pipe, by pulling that
Next undo the 3 10mm bolts that hold the motor on - use either an open ended spanner or 10mm socket (easier)
You can then withdraw the motor - I pushed on the spindle to loosen it first
Its a little fiddly to get out but it does come out ok!
so, heres the offending article - you can see the damage to it, OO'er
new and old parts
In true Haynes style the fitting of the new one is the opposite to removal!
new motor going in
bolt it up ,and fit the multiplug and push on hard the washer hose.
I then operated it before putting the wiper on to allow the spindle to stop in the parked position , as I didnt want to be misaligned and scratch the tailgate.
put the washer jets back on - I cleaned them out with a needle first.
Then put the interior trim back in - I put some larger washers onto the Torx screws as it seems like then had pulled through the trim.
And hey presto it all works!
Hope you find this useful.