Last year I ran the Arntz in a local Cal Club Solo 2 event in BSP (B Street Prepared). I was running with Datsun 240Zs and Corvettes. I was interested in sorting my suspension with new tires and knew that I could not compete without a lot of work (both on my car and my fitness level). It was fun and I feel that I could compete if I devoted myself to the sport. My experience is that if you are not too fast, you can pretty much run any class that you apply for. When you start getting close to trophy levels, the competitors look at you more seriously and protest any questionable element of your car. At that point, you have to make sure your ducks are in a row.
Paul