When I spilt up with my absolute cock of an ex, he really dragged his heels moving his shit out. He'd spent years restoring an old MG which was taking up space in my garage. So I took the inside of the drivers door off and put a marble in there to roll around.

@fesshole

The usual procedure I'm familiar with is put a small ball bearing in hubcap.

@cavyherd @fesshole A little gravel has the same effect while giving you plausible deniability. A ball bearing was obviously put there deliberately to piss somebody off, letting the target know they've been pranked when they find it. Gravel could have been naturally picked up somehow and, on discovery, just makes the target feel like more of a loser.
@Rob_T_Firefly @cavyherd @fesshole The head of a pop rivet in the door would give similar plausible deniability