I have an overhead rifle rack that bolts to the inside of the vehicle just below the head liner. Holds two rifles paralel with the roof of my jeep. It uses two foam lined cradles with velcro straps, and is pretty reliable.(Sorry no pictures) I've had it up some pretty rough roads, and never had an issue with stuff falling out or banging around. Probably not the best idea if yer tall and have a single cab pick up though as it does eat up some head room. I mounted mine in the rear cargo area of my xj and love it!
96 Jeep Cherokee, 4" lift, 31-10.50s, Custom built front, rear bumper, and sliders. OBA, Locrite locker in the rear, Safari roofrack with 6" KC lights, ARB awning, and custom roof mount spare.