So, I am currently dealing with a similar situation, I bought the MKS and the cover was missing, so I am starting from scratch. I bought an aftermarket cover on eBay that claims to fit both 3.7L and 3.5 Eco. Sourced the 4 twist bolts, 4 spacers and also bought a bag of 4 retainers. From the link/forum I posted above, they state the order is bolt, shield, spacer then retainer. This then twists into the body frame to lock in place. This sequence seems like a lot and just curious if someone could post a picture of the sequence installed on shield, AS WELL as if they can take a picture(s) of the shield installed to see what type of gap they have between the shield and body/frame. With the car new to me and never seeing how this was originally installed (and me not feeling comfortable covertly getting down to the ground to look under a random MKS/ Taurus in a parking lot), would be a great help to make sure installed correctly. Last thing I want is a gap too wide and the shield acts like a sail pulling down under the car. Can a picture of how the retain was installed be taken too? Which direction does it go?
BTW, the aftermarket shield I bought on eBay, I attempted to have it installed and the plastic air dam on the inside rub up against the exhaust pipes, so waiting on a response if these universal shields for both 3.7L and 3.5 Eco are safe to use or if they each take a different shield.
I also read that the bolts can come loose and you lose the whole sequence. At around $10 a bolt, I took a Stainless Steel split/lock washer and crimped it close to the bolt in this sequence.
Bolt, Shield, Washer, Spacer then retainer. Hope this works.