I am going to Germany in October and I am sure you can find a few things there, though it won't be cheap.
These are some of the things in the smart Center Trier last October when I went.
Lots of wheel opportunities...so different from what you can get here...
smart security kit.....89 Euro....fits in trunk door.....
Brabus goodies....
Konstanz is great BTW, a bit touristy in summer, but I will never forget the ride across the Bodensee on the ferry. Best way to arrive in that city.