You can download the tracks Intrepid, Cherokee and Magnum at the reference which is on top.

  Developers: Keen, Andree, pitstep 
  It is required: Version 2.11.11 TrackMania United Forever
  Size: 70 KB 

  For Desert we laid up the following routes: Intrepid, Cherokee and Magnum. In the first emphasis is put on a large number of turns, strongly it won't be possible to disperse here. An excellent place for sharpening of skill of game. With Cherokee a situation opposite: of springboards and accelerators it is complete here, but also it is simple to relax and press on gas it won't turn out. Magnum in this three appeared the most difficult track to pass it on "gold", it is necessary to try.

INSTALLATION
   1. Place files with extension of gbx from archive in the following directory: 
  My documents \\TrackMania \\Tracks \\Challenges \\Downloaded.
   2. Come into game, the Solo mode, the Viewing menu, and there select the necessary track from the list.

And the tank model Abrams can be downloaded here.