So, I just got our empeg installed in our 2003 Passat, and I found the oddest thing: I have gotten so used to the steering wheel controls for the factory head unit that I really miss them! Between that and the LONG reach to the volume knob, I've just got to ask:
Has anyone figured out a way to use the stock steering wheel buttons with the empeg? I know there's the proprietary VW bus involved, but has anyone put work in to this problem yet?

Have you looked at this? It doesn't have a specific answer for your Passat, but it's got places to start looking.

Just a quick question.. I was planning on getting a late model Passat, how much pain did the installers have to go through to get it installed? Or was it a pretty straightforward installation?

It was a fairly straight forward install. The only things to keep in mind: there are actually eight speaker outs from the monsoon amp. This is a good thing, but it will require cross-overs. We have the wagon (or estate) model, which lead to some interesting things for installing the amp. In the wagon model, the best place to install the amp is in a small cuby-hole on the left hand site of the hatch area. Unfortunately this is a very small space. So we chose the Alpine V Power 5 channel amp. It's a decent quality amp, and with enough power for a sub as well. That's about the only things I know of besides the usual constant versus switched power reversal in Volkswagens. Be sure to tell the installer about that, I have to take mine back.
You'd think VW would standardize on what the rest of the world is doing, eh?

Nothing like answering your own question. For those looking for a way to continue to use their steering wheel remote, try this one for size: http://www.go2pac.com/products/products_new_detail.cfm?ID=1
from http://www.go2pac.com
I've not tried it yet, but all indications are it will work. I'll post again when I have the final answer.
By the way this should work for many cars, not just VWs.