For her entry representing Germany at the 1999 Venice Biennale, artist Rosemarie Trockel created three films, including a "Brughellian" playground-as-world idyll called Kinderspielplatz, in which kids romping and roding around in eight tricked out toy cars represent our entertainment- and play-centered contemporary culture.
There is , going clockwise from the top of the image above, a wooly VW Beetle; a rusty scrap metal car; a graffiti car, a camper with miniature camping equipment; a snow car [? I don't get this one]; a boat-shaped rubber car; an "Alu-Auto" aluminum race car; a a bristle-covered brush car.
When the private Dutch museum De Pont acquired the Kinderspielplatz cars after the Biennale, Trockel insisted that they not simply be exhibited, but that kids be allowed to actually drive them around. And so on summer Sundays in 1999 and 2000, the battery-powered cars were let loose on a purpose-built track on the De Pont grounds.
It is unclear whether this was a onetime deal or an ongoing tradition.
Update from the comments: DT reader Sven von Kleinraum found a still from the film. I gotta say, that's some pretty low-intensity Bruegellianism going on there.