I read often that people "hear" that the rack breaks. There's about 15 people running RB6's at my local track and I haven't seen ONE person break it. Maybe it's different layouts and skill sets that factor in...
This is the same case here. My wife is now driving a 6 and she isn't exactly a precision driver just yet, but she hasn't broken anything with the car box stock. The only thing I broke was a rear camber plate and that was definitely my fault clipping a tube at the end of a very high speed straight and flipping 20 times right into the wall. I can't believe that's the only thing that broke...