Sure. I would say mine is set up for a self-defense weapon and not really a hunting gun. But since you asked!
I have used this in several different vehicles over the years and it's awesome. This is the Big Sky Rack SBR-1G (the '1G' means 'one gun'; they also make a two gun model 2G which I linked).
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As shown this uses end brackets (model # 'OSH'), which bolt up to the grab handles. The base version just comes with sort of generic smaller end brackets which are good for mounting to coat hook bolts or similar in like a 4Runner cargo area.
I installed it on the third row grab handles so it is accessible by either opening the hatch window and reaching in or when I am sleeping in the back I can access it just above my head.
I will also say that if you want the gun tucked up super tight to the ceiling, as shown, you have to use a shorter gun. The curvature of the roof is pretty tight and my standard adult stock 18.5" bbl shotgun would not fit. I had to get a youth stock for it to get it to clear the curvature of the ceiling. I think most tactical or carbine length rifles should work no problem, or you could hang it slightly lower. I personally like it tight to the ceiling as it is harder to see from outside. This lives in the GX all the time so stealth is important.
Through the rearview mirror:
Prior to installing the Big Sky Rack I just used a couple of Kolpin branded Quik Fist knockoffs attached to my Victory 4x4 platform, but this got in the way of cargo and it was visible if someone peered in: