Polaris width
 

I'm looking at getting a used Polaris 500 looking at a 2006 and 2007. My question is will the ATV fit in the back of a 2000 Ford F-150 truck or will I also need a trailer.

It will fit

i can get my 96 sportsman 500 in the back of my 96 dodge dakota with a tool box. in between the wheel wells, barely. but once i put my new tires on it wont fit . you shouldnt have a problem unless your f150's that is 4 door with the really short bed and you have a tool box. then length could become an issue.

It will fit no problem. If you have a shortbox you'll have to leave the tailgate down. if hauling in a truck I recommend getting your hands on a couple old atv tires(usually fronts off a sport quad work great). I prop them up in front, pull the wheeler up to them, and then strap it down. Keeps it from hitting the front of the box/ back window if you have to jam the brakes quick. Bullydog makes a really cool set-up that mounts from your receiver on the truck to the receiver on your wheeler. It's lockable and adjustable to keep it safe/secured and not resting on the tailgate.