I like it! I don't know if it's what you were going for, but the background almost looks like a distant city, which is very cool. Clouds are great too. I would almost go with a little bit less elevation smoothing on the road, which would lower the embankment in the front a bit. I do like where it cuts through the small ridge farther on though, so it's a balance. The tree shadow on the first bend in the road makes it look like the line has a break in it, maybe move it over a little? There's a pretty good selection of free cars on Sketchfab.
