I was a big fan of Source Karts in GMT, and I recently decided to recreate Lifeless Raceway in Unreal 4, since Accelerate and Workshop support are coming soon. I'm not entirely sure if the workshop will support maps, but it was definitely a learning experience either way. Most of everything was faithful to the original, including tree placements, terrain, wall locations, and signs.
This is still a work in progress.
Here is what I have done so far:
This was completed entirely over the course of about 3 days.