I play CSR when I need a break from RR2 & RR3.
It's fun and a nice diversion... except when I get a car that I just can't figure out when to precisely change gears. I went looking for help and found this incredible spreadsheet. The level of detail and data is amazing to me. So I thought I'd share it in case anyone else plays CSR. Even if you don't, you might want to take a look at it just to see how dedicated and how much work this person has put into it.
CSR Racing v1.7.0 Info (Android)--spreadsheet (Karasaev Aziz)
FYI it paid immediate dividends as I could not win a drag race with the Agera R. I looked it up in the spreadsheet and now I don't lose unless I'm totally unfocused :)