I've loved cars and driving fast since I was 16 and now that I'm older and driving a high end sports car (2009 Audi S5, v8 6spd manual) I'm interested in finding the best way to get my car on a track so I can use it for what it was built for! I am considering joining the SCCA to help get me and my car on the track. Since I currently drive a very nice sports car and am looking at replacing it with either the 2015 Corvette Z06 or 2012 Nissian GT-R in the next year I am not interested in building a race car or spending a huge amount of money modifying a car for the track aside from tires. What I'd love to do is just go out with my daily driver and having some fun on the weekends once a month or so during summer. I'd like to complete against other drivers in similar classed cars, but I'd want to keep everything stock except my tires since it's my daily driver.
I live in the pacific northwest (Portland to be exact), I checked the Portland International Raceways website about track days but they require you to have an instructor in the car which isn't an issue except it cost an extra $200 bringing the total to $500 per session which is crazy expensive IMHO. I see that the SCCA has 3-4 track days per year that I think might be cheaper but I don't know what to expect or if those are open to stock cars like mine or focused on true race cars.
Autocross is another option I'm considering but ever time I've seen autocross it was a tiny track in a mall parking lot with no straights longer than 50 feet or so, which doesn't seem very interesting, and possibly very difficult to race in such a confined space with a car that accelerates like the GT-R or Z06.
Any ideas on places or ways I can get my daily driver on the track every now and then for some friendly amateur competition without spending $500 a session?