The most important thing in my opinion is to figure out how high you need the cap to be. Leer has 3 heights; cab high (100 series), mid high (180 series), and high (122). However, it looks like only the 100 series is available so far for the new Ranger. But I'd check with Leer or a dealer to be...
It looks like they have updated the mold for the tray and that modifications by the buyer may no longer be required. I ordered one, and will post when it arrives...