It isn't just an Alfa thing, the auto wipers were rubbish on my previous car (Renault Laguna). They would change speed irratically, not come on when the screen was wet and come on furiously when screen was pretty much dry. It drove me mad! The lights were worse though, you couldn't turn the auto lights off. There were times around dawn and dusk when they didn't know whether to be on or off and would keep switching, it was especially annoying when going through shade (eg motorway bridges) which would trigger them to come on and go off a few seconds later. This could be part of the reason why the bulbs needed replacing so damn often.