Garry--
Apparently the same stuff is sold here. It is indeed some magic-fluid additive. One bottle per tank.
After I got your note I called the local MB dealer, and he set aside 10 bottles for me, "gratis". (something about owing me, since I sent a neighbor there who bought a new C350 and the salesman wanted to thank me!)
So, I will go pick up my swag and booty today, and dump a bottle in my daily driver. It is a Ford, but I'm sure it all works.
Gus, it wasn't the windshield, it was the fluid. All I drive is newer cars with newer windscreens and new wipers. The additive is foamy and you can see the results immediately; very different than the simple blue methanol fluid I usually use. As Garry notes, it does a remarkable job on bugs--something we all have a lot of here in the summer when driving at night...