I just returned from the first long trip in the ML and she performed flawlessly.
Packed to the gills with my self, two children (3yr and 15 mos), and camping gear. Trip was Charlotte, NC, to York, Maine. Approx 1005 miles traveling at night. Going was 14 hrs, returning was 14.5 hrs stopping only for coffee or fuel. Mileage was a consistent 20 mpg with cruise on 75 mph for hours on end. On the return cruise was set on ~77 mph with multiple tanks coming out to 19.5 mpg. I would refuel with around 350 miles on a tank with the computer reporting 30-50 miles to empty - not wanting to run out in the middle of the night on lonely highways I would rather be safe than sorry.
I'm very please with every aspect of the ML from storage, to handling, to space, to gas mileage. The Inspiration seats are wonderful for 14 hr days. BTW, for safety the underseat lockbox comfortably holds a Glock .40
Tunes provided by through the Bose stereo with changer or Apple iPod via iTrip.
Also first long trip with my upgraded Valentine 1 (upgraded this past winter from the original 8 yr old model). Completely stealth through Virginia, BTW. Faith in the Holy V1.
Well, I think it works pretty good.
Definitely worth the $35 or so price not to have cables hanging all over the place. At medium listening levels I find it great. Not for really jamming out - just burn the CD and insert in the changer if you want lots of volume. The beauty is building a several hour playlist and just letting it play!