So I finally got fed up of listening to the spoiler rattle while driving and closing the hatch. Here's a walk through on how to remove the spoiler apply foam seals and reinstall for rattle free bliss.
Gather the following tools and supplies:

Removal
Disconnect the hatch shelf, it makes for a nice bench to hold tools and hardware. With the hatch open pop off the center cover of the hatch. There are four clips that secure the cover, start at one end and gently but firmly pull on the edges until they pop loose. Remove the two ~1.25" black plugs with a pick or thin gasket scraper, take your time so as not to bugger up the paint. Once remove you now have access to the four nuts that secure the spoiler to the hatch. Use your 10mm deep socket to remove all four being careful not to drop them in the hatch (why you have the magnet). Disconnect the 3rd brake light (connector smack in the middle). Close the hatch.
BTW, never mind the miserable pics edits, they were done freehand on my Chromebook.

Now, grab an end and firmly but gently pull somewhat hard until the end clip is freed. Do the same to the opposite side. Now the fun part, grab the middle of the large section and the leading edge of the small section and give it a good pull just enough to pop the three clips loose. Feed the 3rd brake light wiring through the hole and place on a bench or other protected surface. (Ignore my trashcan bench for picture taking) Once removed grab some cleaner and clean all the dirt and crap from the area under the spoiler paying particular attention to the top and side edges.

Apply 5/16" x 1/4" foam seal along the top edge. Unless you want to see exposed seal I suggest you apply the seal partially on the lower radius of the edge. Also, while on this step I suggest black D-profile EPDM rubber seal, it's more durable and you will see some of the seal color in the gap that's present between the hatch and the spoiler (learn from my initial mistake). Lastly, apply ~6" sections along the outer edge as you see to take up the gap on the sides.

Now with the spoiler on the bench, clean the surfaces well as you did earlier and apply sections of 3/4" x 1/2-7/16" rubber weather seal as highlighted in the pic. The yellow 3M tape is to cover holes that had lost their foam covers to keep water out.

Reassembly
Fish the 3rd brake light wiring though its hole and gently align the four bolt posts with their respective holes. Once aligned firmly press the center section down to engage the clips (they don't seem to make much noise going on versus removal). Once the center section is secure firmly push down the ends until you hear them snap into place. Apply a small amount of blue Loctite to the inside of the nuts, I prefer the gel version because it's easier to apply and less mess. As a side note....when I say a small amount I mean a small amount, the bolts are 5mm for God sake. I've seen the average Joe apply Loctite to bolts like it was anal lube and think he's using Loctite correctly. Run the nuts down just barely snug and then another 1/8 - 1/4 turn. For those that like being anal the proper torque is 69-97inlbs as noted in the MM page 09-16-26 (see below). Reconnect the 3rd brake light, install the center trim cover and two small plugs. Reattach the hatch shelf lanyards to the hatch and test your work.

Just for good measure, below you'll find the IPC for the rear spoiler courtesy of Mazdaspeed Motorsports because I've struck out finding a good IPC picture or one with P/N's at any other online parts house.

All told one can do this solo pretty easily in approximately 30 mins if you have everything on hand. After this you can now enjoy the nice solid thunk when closing the hatch and no rattle going over bumps while driving. Now, grab yourself a cold beverage and contemplate your next project.
Gather the following tools and supplies:
- pick or thin gasket scraper
- 10mm deep socket and ratchet
- magnet.....on a stick
- foam weather stripping
- 3/4" x 7/16" Rubber foam seal Frost King prod # R734
- 5/16" x 1/4" EPDM rubber seal D-profile Frost King prod # V25BK
- cutting device
- blue Loctite (gel is more better)
- some cleaning materials (I used acetone and rags)

Removal
Disconnect the hatch shelf, it makes for a nice bench to hold tools and hardware. With the hatch open pop off the center cover of the hatch. There are four clips that secure the cover, start at one end and gently but firmly pull on the edges until they pop loose. Remove the two ~1.25" black plugs with a pick or thin gasket scraper, take your time so as not to bugger up the paint. Once remove you now have access to the four nuts that secure the spoiler to the hatch. Use your 10mm deep socket to remove all four being careful not to drop them in the hatch (why you have the magnet). Disconnect the 3rd brake light (connector smack in the middle). Close the hatch.
BTW, never mind the miserable pics edits, they were done freehand on my Chromebook.

Now, grab an end and firmly but gently pull somewhat hard until the end clip is freed. Do the same to the opposite side. Now the fun part, grab the middle of the large section and the leading edge of the small section and give it a good pull just enough to pop the three clips loose. Feed the 3rd brake light wiring through the hole and place on a bench or other protected surface. (Ignore my trashcan bench for picture taking) Once removed grab some cleaner and clean all the dirt and crap from the area under the spoiler paying particular attention to the top and side edges.

Apply 5/16" x 1/4" foam seal along the top edge. Unless you want to see exposed seal I suggest you apply the seal partially on the lower radius of the edge. Also, while on this step I suggest black D-profile EPDM rubber seal, it's more durable and you will see some of the seal color in the gap that's present between the hatch and the spoiler (learn from my initial mistake). Lastly, apply ~6" sections along the outer edge as you see to take up the gap on the sides.

Now with the spoiler on the bench, clean the surfaces well as you did earlier and apply sections of 3/4" x 1/2-7/16" rubber weather seal as highlighted in the pic. The yellow 3M tape is to cover holes that had lost their foam covers to keep water out.

Reassembly
Fish the 3rd brake light wiring though its hole and gently align the four bolt posts with their respective holes. Once aligned firmly press the center section down to engage the clips (they don't seem to make much noise going on versus removal). Once the center section is secure firmly push down the ends until you hear them snap into place. Apply a small amount of blue Loctite to the inside of the nuts, I prefer the gel version because it's easier to apply and less mess. As a side note....when I say a small amount I mean a small amount, the bolts are 5mm for God sake. I've seen the average Joe apply Loctite to bolts like it was anal lube and think he's using Loctite correctly. Run the nuts down just barely snug and then another 1/8 - 1/4 turn. For those that like being anal the proper torque is 69-97inlbs as noted in the MM page 09-16-26 (see below). Reconnect the 3rd brake light, install the center trim cover and two small plugs. Reattach the hatch shelf lanyards to the hatch and test your work.

Just for good measure, below you'll find the IPC for the rear spoiler courtesy of Mazdaspeed Motorsports because I've struck out finding a good IPC picture or one with P/N's at any other online parts house.

All told one can do this solo pretty easily in approximately 30 mins if you have everything on hand. After this you can now enjoy the nice solid thunk when closing the hatch and no rattle going over bumps while driving. Now, grab yourself a cold beverage and contemplate your next project.