I love Thunderhill. I ran my 2004 E46 M3 with SMG there about 4 times. I'm more used to Portland International Raceway being only 100 miles away form Portland, but I still love to drive down to Thunderhill, a distance of 400 miles for me. I was using Pilot Sport Cup tires and I had the competition package brakes with the Euro pads. I was running 2:08 times with a passenger. You ran some great times for a novice...good work! I'll bet with a bit more seat time you'll be under 2:10...definitely if you switch to Pilot Sport Cups. Since I only run my car in good weather (yes, I need to get out more), I run the Cup tires as my street tire. Once they warm up, the traction is amazing.
Have fun and be safe. Congrats on your track day.