i.Trek PH-PAD+PB-HRM Headrest Mount for iPad / iPad2
Positives:  Hooks onto back to headrest and grips onto the ipad well.  Negative:  Doesn't hold the ipad in a desired position well.  No matter how much you tighten the wench, the weight of the ipad pulls it downward.  It's alright, works, and is worth what I paid for it.  If I wanted something stellar, I could have paid more.