I wonder about that too, since if you are in a championship, and if you crashed or hit some car in one race, they don't allow you to fix anything between race(which btw, is stupid if they are trying to imitate real world since you usually have days if not weeks between races). I had a bad spell when I did the GT World Championship as I had a few bad crash in one race and ended up 2nd at the end of the series, along with a few other hits. I was worried that my car would be rendered useless if I tried to race the series again. Turned out I don't have enough cash to restore chassis of the RM Z06, so I re-race the series regardless and the car seems fine. Won every race this time around.
I think if they want to implement damage maintenance, fine, but they need to let us know when that needs to happen...