First of all thank you for the mod! Still one suggestion: When driving around in my base it annoys me how to turn around at the end of roads. Would be cool if you could turn around the car via "R".

I'm glad that you are enjoying the mod, although to give due credit - I am not the original author :) I did pick it up for maintenance since it made cars way more usable in bases for myself as well :)

As for car rotation, I could recommend the following mod - it does require that you place the mouse on top of vehicle, but a benefit of it is that it works for any kind of vehicle - trains included:

• https://mods.factorio.com/mod/rotate-vehicles

Would that mod satisfy your needs?

Yes. Thank you for hint :-)

Glad to be of help - I've spent quite a bit of time looking for somewhat "vanilla-friendly" helper mods, and this one was one of them :)