The problem I have with some of these game ideas is that car games are kind of… hard to make on roblox to put it lightly.
Don’t get me wrong it can be done, but very few come out with a fun racing game that isn’t really buggy or nothing. I’m not sure what it is, but cars and roblox don’t mix well but if your able to achieve this then all to you.
I wouldn’t start a game project like this without a good background of modeling and a very talented scripter (either you or someone else), I wouldn’t recommend this if this is your first game that you’ve done, my first game was a simulator and I recommend that. Its a bit boring but it will teach you all the basics you need to know (if your are both a builder or a programmer)
I think that these games could be really cool if you put enough time and dedication into it though.