Im looking for a horror film i believe came out in 2008 but a wider range would be 2006-2012

Started with a group of college students driving a hippie van through the desert, somewhere along the way they break down and end up sheltering in this lantern lit rickety old wooden shack, one of the cast gets tied to the front or back or the van and gets her lower half eaten by a monster and the movie ends by showing her face and that shes still there after the end of the movie. I believe it was rated R, the monster wasnt shown much and I can't find the movie anywhere but I know for a fact it exists, anyone got any ideas?

Its none of these

Wolf Creek, Feast, Reeker, Jeepers Creepers, The Hitcher, The Pack, Dead Stop