All hail the mighty quattro!
Anythings possible with a bit of work, it was my understanding that the b5 a4 andpassat were on a very similar chassis, so length shouldnt be too much of an issue, they can always be chopped and shortened/lengthened easy enough. The passaat arches seem to flair a bit more than the audi's though, so also a bt of work needed to be done there. I'd find someone with the right passat and have a cheeky measure of their cill lenght and start from there. It's not gonna be a simple bolt on, but it could be done imo, either by yourself or by a half competant body shop and you'd have something different from the rest. Got me thinking now.....