I just ordered ACC with mass backing last week for my road runner and installed it friday night. Yeah, the rubbery stuff is a little tough to work with, but ya just gotta trim and check, trim and check, until its right. I probably had 2 inches of overlap between the front and rear carpet, so in a Dodge with a longer wheelbase it would be close.

No complaints from my experience. The interior sound is MUCH quieter!

I tried trimming with heavy upholstery scissors from furniture building, but a utility razor worked best by far. We melted holes for the seat studs with a soldering iron.