Found this elsewhere out on the interwebs:
1) Hood Latch: the most notorious rattle on the truck.
Take your palm and smack on the top of the hood where it meets the grill (don't dent the thing). If you can here a banging your going to need to adjust the latch position. Before you touch the latch, look at the six rubber stoppers in the hood, are they all making contact (you'll see the rub spot)...if not, adjust the two that turn to raise and lower the resting point. If they are good there are just three bolts that you need to loosen to slide the latch mechanism in any direction (do not remove the bolts, just loose enough for it to slide). TAKE A PICTURE with your phone for a reference position. Make sure that when you adjust it, make sure as you bring the hood down to test fitment that it's centered. Only adjust about an 1/16 down at a time until the point when you close the hood and palm hit the area where it meets the grill, it doesn't rattle. You'll know trust me. Had this problem going down the road and hitting bumps in the road and made a racket. Pretty easy right.
2) Inner fender well inserts:
Factory mounts are pretty sparse and cause a tapping sound from the fender area. Where the two pieces come together in the corner, you'll see they make contact when you tap on the liners. Snag some rubbing alcohol and clean one spot in the area where they meet. Use some 1/4in. self-adhesive foam pad (cut a 1in long x 1/2in. piece). I cut up some soft foam pipe wrap I had laying around. Cures that oversight.
3) Vehicle Dynamic Control Module:
Next to the Brake reservoir on the driver's side you'll see a shiny aluminum box with fins. Tap on the top of the unit...if it rattles, grab the back side (toward the firewall side and toward the fender or side without the wires coming out) and gentle pull out on the unit toward the brake reservoir just a touch. Tap on the unit from the top again to see if it was enough. The bracket was actually making contact with the module. (Might have been pushed out of position during assembly).
4) Skid Plate Bolts:
Under the truck, you have 4 bolts toward the front of the skid plate (Two on each side). Take note of the threaded inserts/clips under the skid plate (bumper side). Make sure that the clips are not making contact with the gray lower bumper sheet metal. The problem bolt is on the driver's side most forward bolt insert. The clip rotates toward the sheet metal making contact with the bumper (you'll probably notice a raised rub area on the sheet metal where it was making contact). Use a screw drivers or in my case, a small dowel when you tighten that forward bolt to keep the clip from swinging into the bumper. Easy fix. Also check the license plate mount for any vibration by palm smacking the skid plate while mounted. I flipped my holder upside down to open the air flow area into the oil cooler a bit and made a retaining plate for what is now the top of the plate holder so I have 4 fasteners in the holder and plate instead of two.
5) Lower bumper:
When you have said skid plate removed, palm smack the center lower area of the gray bumper portion. If it rattles like a SOB, grab the lower portion next to the doubled metal brackets and pull straight down a bit at a time until when you palm smack the center underneath, it doesn't rattle like mad.
6) Fog Light Assy:
The fog light modules under the truck are secured by two fasteners. Yet there is an empty stud poking through the mount that was either missed or they thought it wasn't necessary. So to solve another rattle after tapping on the module, I added a lock nut (M6x1.0 I think) to the stud. Problem Solved.
7) Driver's and Passenger's side hood baffles by wipers:
Found mine lose as heck, retainer pins and rubber pegs not fastened correctly so that find alone fixed the passenger side. Driver's side would tap against the fender bead roll. So I once again used a piece of soft self-adhesive foam and bent it around the metal where it made contact with the plastic baffle.
8) Passenger Forward Relay box:
Only has a few things inside, but tap it from the side and it sounds like parts are just bouncing around in there. If you take the cover off, you'll notice the forward most relay (although electrically secure) is not physically. I once again used a piece of foam tucked between the two relays to stop the turkey from wiggling around.
9) Steering shaft Loose/Rattle:
Waiting for an updated part (sector shaft) to fix the issue. When truck is off you can feel a bit of play, but oddly enough, is only really noticeable when making sweeping turns to the left and hitting small bumps while moving. More to come as I find them.