The Front Runner barbecue grate clips right into the center of a truck-mounted spare tire, for easy access at camp and streamline storage on the road. It even looks cool while not in use, if you're into that 80's-aerodynamic accessory style.
If you keep a spare tire on the back of your 4x4, this cool stainless steel grate might finally convince you to replace the Tweety Bird cover you can't let go of. Having a big flat fireproof surface like this really makes camp cooking easier, and being able to keep it out of the way is a solid bonus.
The stainless steel grate will fit on your wheel if your tires are between 29" and 35", and costs around $125. If you're fancy with a torch, I'm sure you could knock one up yourself as well.
Hat tip to RoversNorth, images via Front Runner