Faro, last year, released free software called Scenect that enables 3d Laserscanning of objects with the Microsoft Kinect or Asus Xtion devices. You can check it out here. Not sure how useful this would be to most modders, but I've not seen it discussed very much and thought I'd throw it out there. Practicallly speaking, scanning cars or tracks isn't very likely. But perhaps scanning high detail scale car models could yield interesting results. http://www.faro.com/scenect/
I'd rather go the arial drone capture way, much easier for instant LiDAR - but still has it's costs... http://youtu.be/Wl4VWZ2t0-s