I live in southeastern Wisconsin, and haven't encountered too many rude drivers. Most give plenty of room when they pass, and only occasionally will they honk. I'm just north of Milwaukee, and even riding into the north side I haven't encountered more than the occasional idiot driver. This seems to be an exceptionally bike-friendly area, though. I did the Trek 100 out in Waterloo in June, and drivers were very friendly - of course, Trek is a major company for that small town.

Daytrip, thanks for posting your ride - I've been looking for areas with more hills, and we certainly don't have too many here!