Probably because it somehow clips into the road.
Not sure why though!
Sorry about that! I don't have a Mac myself, so that makes it a bit more difficult to develop for it.
Also Macs seem to have pretty strict requirements for running "untrusted" software.
I might still release a Mac version later, but it probably wouldn't be as well supported as the Windows & Linux versions.
Maybe! I've been looking into some new ways of creating shadows. Some form of shadow volume algorithm might work!
I tried using post-processed ambient occlusion, but it didn't look very good in my opinion. Generating ambient occlusion maps when the track loads might be possible, but would probably use too much resources.