I had this issue. I noticed a squeak and found it to be the rubber rubbing the cab. Took it back to dealership and after a little back and forth they sent me to body shop. They aligned it betted that factory.
I went for the cheap horse mat from Tractor Supply. Somewhere in this forum it was recommended and it seems to work really well. Just had to cut it to fit, which was hard due to the thickness.
https://www.tractorsupply.com/tsc/product/4-ft-x-6-ft-x-3-4-in-thick-rubber-stall-mat?cm_vc=-10005
Mine is squeaking too. I found the rubber piece between the cab and bed was uneven on both sides. One had a large gap, whereas the other was touching. Still trying to get the dealer to repair and it been 2 months so far. Could be off base here, but worth checking.
Just received mine in Dec 20 2019 (Merry Christmas to me!). This thing is awesome. I have always been a Jeep/Truck guy, so this fits the bill perfectly.
It was pricey, but you get what you pay for, and its only money, right?