indeed, the car is from the template, i would have wanted to replace it with another skeletal mesh, but for some reason that broke the template due to C++ integration which i don't really know much about. i tried to just have two meshes in there, one for driving and collisions, and one for looks, but i couldn't get the wheel animations to work. so i decided to go back to the template car which i know worked.
As for the checkpoint and arrow system, i made this myself as a slight tool if you got flipped. in the early testing i already noticed that the car could sometimes be a bit twitchy and have a tendency to land on it's back. So as a means of orientation i decided to add some checkpoints with an arrow pointing to the checkpoints in order to get the player moving in the right direction again after a vehicle flip had disoriented them.
About the checkpoints being very precise, yes, I tried looking into pointing to the nearest point within a volume, but that was a lot of work, so i opted for pointing towards a single point (the center of the collision volume). I thought that this would be plenty because it's meant as general orientation anyways.