No, this isn't an advertisement . . . and no, I don't own one. I saw a few of these hitch racks up in Whistler last week and they struck me as one of THE coolest rear-mount racks I've ever seen. They are made by a company in Vancouver, BC and will hold any mountain bike comfortably and compactly.
I am tired of trying to make normal parallel-strut 'hanger'-type hitch racks work with all the different suspension variations and once you start getting out to 3 and 4 bikes with the horizontal rear carriers, they start hanging waaaayyyyy out back.
I just wanted to throw this out for the crowd that there is another alternative to consider now if you have to carry a lot of bikes on a car/SUV. They come as 2-, 4-, and 6-bike models. Check it out: