Well, I'm no lawyer but I think there's some wiggle room in the definition of 'off-road'.

I would be interested to hear about a the regular 4x4 of the highlander, except that it's also designed with the same unibody construction.

Xterra/4Runner get about 19mpg remember? If they put out a 4Runner Hybrid with a true 4x4 system I'd trade in my Highlander in about 2 minutes!