http://www.indiegogo.com/projects/modular-race-track-kit/x/2305754

The Modular Race Track Kit designed by and for game developers. It's designed from the ground up with mobile optimization in mind, so it can be used within mobile phone projects, tablet projects and or PC/Mac. The kit itself is completed, so there is no gamble waiting for it to be delivered at a future date. Backers will get the download link to this project and all bonuses as soon as I receive the email.

Drive around a sample track created with the kit (requires Unity webplayer plugin) :

http://dl.dropboxusercontent.com/u/16956434/Modular_Race_Track_Kit/ModularRaceTrackKitSampleTrack/ModularRaceTrackKitSampleTrack.html

And a bonus perk with the kit:

All (16) Low Poly Vehicles including (3) LODs for each.

LOD Information

Now included with this pack, is another full pack. The complete city pack! You'll get this entire pack alongside the Low Poly Car Pack + Modular Race Track Kit. This new pack will allow you to fully populate massive cities. These assets are meant to be versatile for both webplayer and mobile projects. They could be used for first person zombie apocalypse games, an overhead RTS-style game, a flight simulation/military aircraft combat game and my personal favorite - car racing games!

Currently the asset kit contains 155 unique elements. These are a combination of "clean" looking versions and "destroyed" or worn out versions. The textures are in PSD, PNG and TGA formats. They range in size from 128 x 128 pixels to 512 x 512 pixels. The 3d models are FBX file format.