I saw a convoy of 8 heavily disguised W220 S-Classes a couple of months before the car was introduced and a couple of undisguised current-model A3's a couple of weeks before first pics were released. And a truck full of disguised test cars last winter, but it was going the other way in a heavy snowstorm so there's no telling what those cars were.

Also last winter, while driving on the local motorway I once passed 15(!) German-registered trucks packed with brand new German-registered BMW's, heading north. BMW driver training, I suppose.
If I had the time I'd take my camera and head up north right now.