Porcupine Rim features 15 miles of hiking trails near Moab, UT.
The trailhead is located on Sand Flats Road, the same road as the World famous Slickrock Bike Trail. 6 1/2 miles past Slickrock is the trailhead for Porcupine Rim. It is a dirt/gravel road from Slickrock on, but you should have no problem in a car.
http://www.tripleblaze.com/trail.php?c=3&i=222