But, it doesn't say anything about the Stuff(not drivers) training. I see it is not possible, BUT do they gain/loss star points according to race performance, or are they stuck as you got them in the first place?
It's very frustrating that a TD(for example) you hire at the start of the season gets max rating and then at mid season there are, 2,3 levels below you. To hire a TD every 10 races would be stupid and expensive.