Took it in for the annual emissions test so I can renew the registration. It sucks that I'm in one of the few counties in Texas where the EPA mandates emission testing.
Dongar products are available on Amazon.
Amazon.com: Dongar Dashcam Power Adapter (5-pin Type F) for Select Ford Vehicles. Compatible with Mach-E, Bronco Sport, Explorer and More. Built-in USB Power Source, Connects to Rearview Mirror, Easy to Install : Electronics
I also have the MBRP catback and I don't recall the docs saying anything about unequal length pipes on the mid-pipe. Mine was equal length like yours and fits perfectly. I'd do what TeamHippo suggested and install with everything loose to be sure but I'll wager it's going to fit OK.
That sounds like the fruitless search I want on trying to find the rattle.
Try the rear seat thing. There's nothing to lose and it takes just a few minutes.
Just as an experiment, put the rear seats down and see if that makes a difference. I had a rattle that was hard to pinpoint. I thought it might be the rear suspension or the exhaust. It turned out to be the rear seat latches. A little grease fixed them right up
Here's the reply they just sent me:
"Our Form Taillights mount and adjust exactly the same as the OEM lamps."
I dunno what to say. When I upgrade, I'm going to try adjusting the screws (if it needs it). If it breaks, I'll point out their reply and ask for replacements.
I have plenty of nylon washers so that's certainly an option.
I did contact Form on their web page to see if the screws are adjustable like the factory lights. I'll post what they say here when they reply. It'll be good info even though you already have a working solution.