ACC mass backed sure seemed to fit well. Since the backing is molded to the shape of the floor pan, there’s no adjusting the carpet location when installing. Plenty of excess material on all sides, so never any area where it came up short.
I’ve only installed one mass backed set, so I’m no expert but based on my experience it seems like the best carpet choice to me.
Agreed, I've done several mass backed ACC carpets, Mopar and brand X and IMHO it's the best fitting and looking carpet in regards to how it lays out and retains it shape, no wrinkles, smooth contours due to the membrane, generally I opt for an ACC carpet made in cut high pile w/mass backing, not a fan of the OEM 80/20 loop.....
Mike
few pics of standard backing vs mass backing for those not acquainted
