Here is my first map!
The goal with the start is to gather enough speed to make the jumps smoothly, which will allow you to skip the freewheel. I believe this will help some players learn how to drive dirt smoothly, and how to keep control of your car while maintaining speed.
The second half is all about angling your car to keep as much speed as you can through the field and dirt, and in the ending you're meant to cut through the grass both before and after the last CP.
The AT is challenging but certainly beatable, i expect to see .4x and maybe even .3x, although i don't believe .2x is possible - unless you get some lucky jump over the fence into the finish, or something.
edit: well, rip! riolu got a .35 with an ending improvable by ~.2x, and then lars pointed out that this finish has a bugfin - which in this case saves a further 1.1 seconds! so an ideal run could in fact be a 44.9x or so, although you have to be incredibly fast for that...