I was having a hard time finding a spot to mount a gun on the P500. Finally, I affixed two gun mounts [Kolpin 21535 Rhino X-Large Grip - UTV Mount] on the roll cage under the roof. I've seen some guys putting a double cradle up there. I thought that cradle was a little pricey and not particularly adjustable.
It's hard to get good images under there, but you get the idea. The Amazon.com link is
Amazon.com: Kolpin 21535 Rhino X-Large Grip - UTV Mount: Automotive
The mounts are rubbery and grippy. Almost too grippy. These mounts are very adjustable so you can affix them pretty much anywhere you want. There's lots of room under the roof and the guns will remain completely out of the rain. When I got my P5, I thought there was too much headroom under the Honda roof. With the guns in place, there is just enough headroom. Honda engineering. The guns will stay clean, because although the entire machine gets muddy from mist and spray, there isn't any dirt appearing on the underside of that roof. US price was around $28 per gun so $56 for what appears in the images. I got a similar Canadian price at Cabelas.
The guns ride nice. The mounts appear pretty tough so I'm sure they'll handle longs rides no problem. These mounts are for transporting the guns. It's alittle hard to deploy the guns quickly, so if you were road hunting, you'd waste too many precious seconds unhooking them.
My next mod is to find an elegant way to stand a gun up on the floor and strap it to the dash.
FYI Al