I know you're an engine guy, I try to pay attention to what's going on behind the flywheel.
I've been told that teams will cut certain proprietary bars out their old cars before selling them to prevent anyone from knowing their particular configuration. Truth or BS? How much are teams involved in the design of the chassis? Do they have they're own requirements/configurations that they like? Or do they rely on the builder to provide what's best? Do you use a certain amount of flex by design in the chassis or do you try to make it stiff and use suspension adjustments and components for desired changes and control? Between testing and racing, I expect these cars get a lot more laps than people may realize? How many runs will you typically get on a car before it's considered used up and sold?
I would say maybe years back somebody like WJ or bob Glidden might cut bars out but nobody would these days. I now Jason and Greg's cars probably have thousands of runs on them. Some teams might have their own way of building a car but mostly Jerry Haas does every car basically the same and they work.
