Komen Drive for the cure
I drove for the cure about a month ago with a friend of mine. We drove a 745, 330Cic(Step), X5, and Z3(manual). Actually, I took the manual out 3 times.
It was a GREAT experience - everything you would expect from BMW. The people there were very courteous and helpful. There was a cookout with free food and drinks.
If you want to drive a few different cars, I recommend going early in the day. My registration was for a 330Ci at 11am but i got there at 10 and was able to drive all the other vehicles too. It got kind of busy around 11:30. It's kind of like an amusement park. When you get there early you have free reign and can ride the rides over and over again without waiting in line!
My trek in the city was an 8.2 mile stretch which had a good variety of conditions. They give you a map with turn by turn instructions. I think it's more so you don't get lost than it is to limit your driving experience. Also, they like to be able to know how long you'll be gone so they can keep the event running smoothly and not have people wait too long to drive.
I hope you have a blast!