Hi 4rings,
I have been working on this too. There is a list of faceplates here
https://sslrelay.com/s74326199.onean...dex.shopscript
Some are single to single din, others are double din to single din with a storage shelf to fill out the rest of the space. According to people here in Taiwan, the only want to get a double din faceplate is to get the one with the storage compartment, and cut it out. Do you have a single din stereo now or have the double din and want to put in a single din aftermarket HU?
The other issue to really consider is anchoring the stereo within the assembly. I have talked to a few shops here (professional quality) and even they said the only way to mount a double din into the audi double din plus slot is to install the faceplate, and 'stick' the HU to the faceplate and improvise in the back-end to keep things attached.
There is also a post here
http://forums.fourtitude.com/zerothread?id=2496707 where the guy did some major upgrades to his stereo. Interestingly, he only shows pics of the HU taken at night...so that might be indicative of something.
So far, I have been unable to resolve two fundamental problems that prevent me from changing out my HU
1) The assembly....the Audi slot is simply non-standard, so putting in the 2 din stereo in the slot is tricky in terms of securing it.
2) Because of the extra space of the aesthetics of the solutions I have found are questionable. For example, hacking out the storage compartment of the double din faceplate. Doesn't sound pretty.
Having said that, I have seen pics of Pioneer Avic-3s installed that look pretty good.