The final version of this track is now done. The biggest improvements since last time are added elevation, short circuit, dirt track, grandstands and a small lake.
The sketchup file is available to download below (warning: 35mb download and runs very slow with shadows).
https://www.dropbox.com/s/nqr49zqm4p...n%20Hills2.skp
Overview of the track
Pit lane
Turn 4 hill
Turn 6
View towards Turn 8
The lake between Turns 9 and 10
Turns 15 and 16
Oval
Dirt track