On coach buses can you go to the bathroom where does it go?
what is it? I've always been wondering.
a holding tank. then emptied out later.
There's usually either a tank where it's kept in until you stop, or (depending on the route) they might just let it out on the road (in this case it would have to be an out of the way spot).
On the windshield of the car behind.
In your mouth
Into the radiator...
A holding tank, same as on airplanes.