I use a bed extender like the one above(mine is home made) for my 12' Jon. I drive a f150 that has a toolbox against the cab. With the extender it leaves about a foot of boat past the support. I can back down far enough to push the boat into the water and also to drive the boat part of the way back on. I plan to buy a trailer, just looking for the right deal. I have the boat on the truck right now, I'll try to go out at lunch and snap a picture.
David