I took my 545i to the track in Pueblo, Colorado last week first time. Ambient temps were 70's. Normally, the iDrive boots right up after first click of the key, but after a couple of hours of runs and cool downs, the iDrive took considerably longer to boot up. Is this normal?

Also, what is the strategy for cooling down after runs, open hood or not?

Track is 2.2 miles, 10 turns road course, http://www.pueblomotorsportspark.com/map.htm