Just saw this today. If it's new, i say its a good deal.
my personal opinion is that quick clamps are a horrible idea. Leaving any firearm unsecure aka unlocked and out in the open is pretty irresponsible. Forget hi-fiving cops, how about a criminal walking by your vehicle.
If you really want to mount it to the hatch, do it right and look at companies that specialize in firearm mounting systems for vehicles such as
santacruzgunlocks.com.
Also, not sure about the hatch struts on the 3rd gens but most likely you'll need to swap the stock ones out if you plan to add a 6-9lbs AR, 2 lbs shovel and a 4 lbs axe to it.
Before you do anything, you should check the gun laws in your state. Not something you want to go into it blindly.