[PT Cruiser]

If fear of a big crash damage bill is holding you back, one way to step up the risk level gradually (as per Gerardo's post) is to run races at tracks that have lots of runoff room. Although EVERY track has one or two places where you can write off a car with one stupid mistake, some places, such as Mosport or Watkins Glen will bite you just about anywhere you make a mistake, whereas tracks such as Homestead, VIR or Barber Motorsports park have quite a few places where you can go off big time and collect nothing but some grass clippings and/or loose gravel. After you've gotten comfortable pushing limits in a relatively safe environment, and gain confedence that you understand the car well enough to detect and correct small mistakes before they become big ones (and have the ability to anticipate how the car is likely to react as you get closer to the edge), you'll find that you can go back to a relatively intimidating place like Road Atlanta and go faster, because you've gained confidence in your ability to take care of yourself closer to the limit.