I've done it. Dead easy.
To be honest don't miss the wiper either, the missus has a BMW Coupe so that also has no rear wiper, so its normal now.
Venom Motorsport do a rear wiper blanking kit, which is a piece of black glass that fits into the hole on a Mk4 golf, and fits into the Audi hole with about 0.5mm worth of sanding on the outside edge.
Thing is, the glass insert is £20!!! All it is is a piece of black smoked glass that matches the black glass in the rear screen, with a slightly larger piece of clear glass attached on the back.
The kit also comes with glass adhesive.
When fitted you can see it, but as its glass its way less obvious than most other solutions.
The other, MUCH cheaper option is to buy a plastic grommet from the dealers, which is about £2, and glue it in using clear silicon sealant.
You pay's your money, makes your choice so to speak.
As for the actual process, you remove two screws where the handle is on the hatch fascia, and pull hard, the fascia will come away.
You then flip up the rear wiper cover on the outisde of the car, and remove the wiper.
Then undo the 4 screws on the rear wiper motor, release the power and water connections.
Cable tie the power, and bend over then bind up the water tube so it cant squirt any water.
Do your hole filling by methods described above and re-attach fascia.
