The BMW is a 2004. It's a 6 speed manual. I get in the mid 30's on the highway in 6th gear running about 75 to 80 mph. Around town, we get in the upper 20's, when I can't keep my foot out if it we get mid 20's. When I have the rack with the Thule box on it, I get upper 20's on the highway.
If you are running performance tires on the 330xi it sucks in the snow. The snow tires are key. We definatly drove out of our fairly long driveway in over a foot of snow many times this winter, car did great.
We had an Audi A4 quattro before the bmw and it was great in snow. I drove that thing in snow deeper than the hood of the car and never had a problem. Actually the only problem after driving in snow that deep was all the snow that would get packed up in the chassis of the car, so when you got on the highway it would be a rough ride until all that snow fell off the car.