I'm certain that GM is using the same "weight rated" lower motor mount in the 3.6L AWD models as they use in the 3.4L models. These motor mounts can't withstand the additional weight of the 3.6L, plus the transfer case associated with the 3.6L CXL Plus models only add to this additional, unaccounted weight. I have been on schedule replacing this motor mount about one a year since 2010. Once the motor mount completely collapses, the engine then makes direct contact with the frame, and as a result, you feel excessive engine vibration, and hear a metal-on-metal grinding noise when making a hard left turn (causing weight of the engine to shift to the right side where the motor is located, and can easily be mistaken for a bad shock, bushing, etc.). Since this design flaw doesn't result in a safety issue (at least none that I can think of), I'm sure GM will care less about fixing this issue. GM only seems to respond to large law suites that hit their pocket book in a bid way.