Usually those are trains that ride on rails, but sometimes it just so happens that cars fly over them. Road rules can be somewhat tricky, especially when you're driving back from a wine-tasting. If you happen to spot a red Citroën 2CV above the horizon, don't be surprised. It's only Prague boys having had too much to drink.
Honza (Kryštof Hádek) and Jirka (Lukáš Langmajer) were swishing by on a local road with considerable dose of wine, both in their bodies and their car. When they pull over to pick up the hitchhiking girl Klárka (Tereza Voříšková) and Honza takes over the wheel, it only takes a brief moment of inattention and overlooking the level crossing, and the crew of three is in for a short observatory flight. Luckily, their car survived the incident, and so did the new wine in it.
If you take the road from the village Šakvice do Starovičky (or the other way round), the unlucky spot from the film Grapes is found about halfway. Fun fact - this scene was filmed last, in case the car would fall into pieces during the stunt.