The Twin Cities are much like Winnipeg in one aspect - it is absolutely necessary to have an automobile to get around. As I mentioned previously, the metropolitain Twin Cities area is made up of many cities - which is confusing (expecially when trying to reserve a hotel room from Winnipeg). We stayed in South St. Paul. Even to eat, we had to travel 10 minutes by car.
The road system is fast paced - lots of merging, etc. You absolutely need a map. Figure out where you are going before starting the car, or have an intelligent navigator (my wife was happy that our 17 year old son took on that role).
Minneapolis is great looking, modern city with perfect roads and highway scheme. Of course as a tourist you won't have much time to get used to where 5 north of 7 south will take you. We didn't...
We were driving around and got lost number of times. I remember we were at one point next to Mississipi River and we wanted to get to the more attractive other side. It was so close, but in order to get there we had to change 2 highways, and guess what - we got lost again and found this other side two hours later...frustration never ends!
My worst mistake was that I thought I'd get around with public transport. I found out that that wasn't the case for me. I stayed a bit outside the city center. If I didn't want to pay huge bills in taxis, I'd have to rent a car. Financially it got up to be a little under break even (for two persons in a week).