I have been down the track every season since 1974, I will be 66 this spring, and I have been asking myself the same question. My issues are I don't take sitting in a fire suit on a 100 degree day like I used to, I have arthritis and after a 6 hour tow to the race I can hardly walk after getting out of the truck, but the big thing is my car is getting faster than the driver, cannot cut a light like I used to, and things seem to happen a lot faster than they used to. And finanically it is costing more to race every year. I might build a slower car, just thinking out loud. But I will mess with cars until the day I die no question about that.