The first day is great, but it really just feels like prep for the second day, during which the drivers go without instructors and simply get to drive as fast as they can in 15-20 minute sessions with coaching between sessions. They usually give one or two corrections after each round, but a driver who asks questions can unlock dozens more. I was there to have fun, but I also really wanted to learn and get faster, and the instructors walked the fine line of catering to me and catering to the people who are just looking to an experience and don't want to be overwhelmed.
By the end of the day, I'd taken my time from 1:16 down to 1:07, and was the fastest in the less experienced of the two groups in all but one session, in which Emilg Chung of www.autoniche.ca beat me by just a few tenths of a second and posted the best time for our group of the day. We were discussing a re-match almost immediately.
Passing is allowed, but only with direction from the person in front and on one part of the track. If you want to learn to pass another driver in a corner, you'll have to stay for the third day.
Pro Tip: Drink lots of water, and always pee right before getting in the car. Those lap belts get strapped down tight and mine was pressing right on my bladder for the whole session.