I am actually cycling in the Czech Republic right now, but slept tonight about 20m over the border in Germany. Definitely feel now like this tour is coming to an end. Still a good week to go.
I've had the fries with fried cheese in the Czech Republic. They also didn't salt the fries, like sometimes in Belgium, haha. The supermarkets along the border here in the ore mountains absolutely suck, they're all some 'duty free' type shops for the Germans coming over the border to buy something cheap. Handbags, liquor, cigarettes, huge packs of Haribo. Was not able to find any joghurt for my müsli, so i will have a snickers for breakfast.
There's quite a lot more services offered on the Czech side of the border, most notably faked brands stuff and prostitution, plus drugs (lots of drugs) and, if you ask nicely, even weapons.
It's quite the show. The bazillion cars from Germany are not there only for the cheap chocolates.
Where i am riding there are hardly any cars, most of it is completely car free, have not experienced what you described yet at all. But i remember having heard about it too.