I actually just got done this weekend putting that product on "Silver"....She's my '06 X.
These are a decent enough product, but would more then likely stick with the black powder coated aluminum. The 12g steel are very durable, but have hurdles that will need to be addressed.
1st off it took a very lengthy amount of time to get them to line up and the holes don't always seem to be 100% accurate. With patience and determination it was unnecessary to use any type of gasket behind them. They come with black colored rivets. Use a 3/16" drill bit to make the holes. I would suggest removing the inner wheel well sections nearest the rear and having multiple C-clamps and protective rubber padding or plywood squares to hold the pieces while drilling. I just spoke to WP yesterday about some of the fitment issues and some of the holes not quite lining up with absolute accuracy. They are aware of issues with hinge side being slightly off.
Overall I would give this project a technical level of 4 or 5 and it requires allot of accuracy. Check 3 times drill once.
I chose to use spray on Lithium grease on the tub and on the corner gaurds to protect against rust. According to WP there will be approximately a 1/4" space at the rear most contour. I refused to accept that and got mine to with in a 1/16" - 1/8".... I also used spray Silicon on each of the rivets while inserting them as to aid in installation and rust retardation.
Spraying any type of LUBE on there is not wise. It will attract dirt and sand. And that wil grind into the paint. Like I said above I used a colored RTV on the back edge. So when the rivets putted tight it oozed out a little. i then just too a rag and wiped off the excess. Do this on ALL the edges, even the holes for the tail lights. You want to seal the panel up tight so no water or crud gets in.
DO NOT USE self tapping screws. They will fall out. the metal is too thin to hold them in.
You dont want to leave the back of that guard open to salt and dirt. Seal it and forget it.
I am old and dont care, But when I give you advice you can take to bank that I learned the hard way and dont want you to repeat a mistake I made.
As long as you are absolutely 100+% sure everything is completly sealed with no gaps. Examples: gas filler, around taillights, and each and every screw or rivet hole. Also what about condensation that could form between the inner body and the armor plates due to temperature differences? As for your tires, have you ever noticed how the inside of your rims can rust? This happens because moisture was introduced with the air. That's why air compressors have moisture traps. I'm sure not suggesting you punch holes in your tires! Also I suggested leaving the bottom open not the back.
I dont have time to explain all, but compressed air and the gap between the body and armor is 2 different things. The amount of moisture in the gap is almost a moot point. Seal it up and forget about it.