I was going to wait until I took delivery of my 2021 2500 to join this forum but a technical question has been asked by my guy who is going to do a couple of mods for me. Specifically, has anyone experienced or aware of any issue that impacts the installation of am MX4 cover? I have found limited info on the web and what I did read suggested it may be a 1500 model issue and also possibly the rails from the factory installed cover are different or changes the rails for a aftermarket cover? Any insight would be very much appreciated.