I've swapped plug wires by accident before. Car ran like $hit.
I've also had sockets fall into places in the engine bay where they shouldn't be.
I've also discovered that if you drive at least 50mph in the pouring rain with a mis-aligned sunroof (and of course stuck in the open position), you won't get wet. The problem is, the idiots in front of you won't go 50 mph in a downpour.
Driving a 928 is nice. Driving an old 928 when its sunroof is stuck open in the rain and everyone else in traffic is having a good laugh....priceless.