Time for some light-hearted banter.
What's the dumbest thing you've ever done to, for, or because of your Opel?
I'll start off:
I once spent weeks with a milling machine carving out a block of aluminum for a cold air intake adapter for my GT's Weber. I flowed it and filed it and polished it to a high luster.
Then I tried putting it on the car.
I made the inlet for the cold air ducting too small to attach the ducting to it. So small, in fact, that it flowed less air than the barrels in the carb. I also made it too tall and couldn't close the hood without it hitting. It was such an unsalvagable cock-up that it went straight in the recyclables bin.