I got my 3 ('04 2.3) back in Nov and I've noticed that whenever the temp drops below freezing (I live in Minnesota so this happens quite regularly) the horn stops working. It doesn't work when I push on the steering wheel and it also doesn't work when I lock it. Any suggestions on what's going on here? Does anyone else have this problem?

 

I had the opposite problem w/ my '92 dx, when it got really cold, the horn would start blowing and not stop.

 

I suppose that when it gets really cold the connectors could be shrinking a little bit, and then when the car heats up (or it's warmer) it's expanding a bit and making contact. I'd suggest checking the connection to see if that makes a difference. And while you're down there go ahead and put in a better horn.