I must really suck, I tried both methods above for 30 minutes and couldn't get it. Saw another solution on YT full credit to: Nillzilla & Rethgaa
Achievement actually pops at 1:38. They give a brief explanation during the beginning.
Try this if you're having issues with the other methods. Basically the middle ramp on the loading screen map is 75m. It's a lot easier doing it over that ramp rather than a large hill.