Do what Zimm is doing, do it exactly as he is doing. If he is getting SWR reading that he claims, he has done it about perfect.
The only thing I would question in his set up is where he gets his power. Power coming straight from your battery will be the cleanest but if connect to your cig lighter and get no extra noise than it is just fine.
DO NOT ADD the folding piece after you tune your antenna. Adding this too the antenna changes things. I would recommend against the folding mount, when I looked in to them they seemed to be a weak point. Get a quick disconnect or a spring but install it all before you tune your antenna. I would also but a tennis ball or hand ball on the antenna where it could hit the body esp if you get a spring.
The most important part of your set up will be how the antenna is mounted. You need a good ground. Anything that attaches to the body such as a rack, a door, a hood, a tailgate etc my not provide a good ground. There will be a layer of paint between the hinge of whatever attaches to the body that could make the ground less effective. The antenna you see sticking out of the vehicle is only part of the actual the antenna, the rest of your antenna is the actual vehicle.
Antennas: The Wilson you see in one of the previous post is a base mounted antennas, it guts are in the base so it the entire antenna should be on top of the vehicle, . Zimm’s antenna (and most fiberglass antennas) are top loaded and ideally you want a foot or more stick above the vehicle. You will have to make some tradeoffs here. The better your antenna is setup up for transmitting and receiving the more vulnerable it will be to trail damage.