Yesterday on my way home from work I saw a Prius with a 2" receiver hitch on it. Whatever that guy tows that needs a 2" has got to take an MPG hit. Anyway, a rear hitch mounted cargo carrier may have less FE impact than something on the roof.

And about rear visibility, the side mirrors tell you much more than the rear view can. Everyone should use them more, so adapting to that may actually make you a better driver. The "zero rear visibility" observation is from someone who doesn't appreciate that most of the usable rearward information comes from the side mirrors. If you don't use them you're missing out on a lot of data.

As for the roof rack... I use a yakima setup with an older rocket box on my Xterra and formerly on a Forester. It effects FE mildly but not very much in those vehicles, 1-2 mpg at most. Those rooftop boxes actually have a huge amount of volume. My skinny one can hold a set of golf clubs, three milk crates, and a LOT of stuff packed in around the sides of those. If you are clever and pack in smaller bags rather than huge suitcases, you'll be able to fit an amazing amount of stuff up there. Plus the racks can be useful for other stuff like bikes and skiis, so it's not a wasted investment. You could also consider a "basket case" rack for the roof rack, on which you can put a duffel system or a few of those plastic trunks.

I have bought nearly all of my yakima equipment on ebay. Figure out what parts you need, search well, and find good deals--you can save a lot of money that way, you can get set up with a rack for less than $150. Trouble is the ebay possibility may only apply to the racks because the cargo boxes themselves are too big to ship (except the short ones), so you may have to find one locally. The good thing about that is it makes them cheaper because there are fewer buyers locally. Try craigslist. I have found good prices on several there, and if you find one in a nearby city to buy, you may also be able to use craigs list to find a ride for it. It takes a little finesse and flexibility but it can really save a lot of money and hassle.

Good luck.

Thanks for the great advice zimbop.

Roof rack from ebay sounds like a good idea. Do I just trust the seller on ebay about fitment? Do I need to know my crossbar width, etc.?

Last night I did come up with an imperfect solution (although all options have the negatives). Mounting the duffel directly on the trunk did not work well as the top trunk-panel-grabbers wanted to be pulled laterally and not straight up over the duffel.

However, I found the right straps for my Yakima REAR-mounted bike rack (it was last mounted on our old bimmer-wagon). Once that was on securely it was fairly easy to bungee the waterproof duffel on top of that. And I mounted it not on the crossbars for the bikes, rather the part of the frame that rest upon the top of the trunk. I think this will lessen possible scratches AND let me bring the bikes if I want to get nuts.

We went on a test run to the park and the duffel never waivered. Oh, it also still allows trunk access. In the duffell was our big tent, queen-size blow-up mattress, pump, and room for at least all our bedding. That leaves tons of room in the car for everything else.

I really don't want to spring for all the cool roof stuff just yet. Hopefully in a couple years we'll be packing all this stuff in out solar-hybrid-diesel minivan.

Thanks all for your help and I will definitely take pictures when our pack mule is fully loaded.

http://greenhybrid.com/compare/mileage/car/3686.html

http://greenhybrid.com/compare/mileage/car/4955.html

Most yakima gear fits many models so you'll restrict your options if you look for sellers who took it off your exact model, and in general they're not always reliable for what vehicles their stuff fits. The best approach for this is to go to yakima.com and fit out your vehicle. Figure out what towers and clips you need, and the suggested crossbar length, and take that info to ebay. Search for the part numbers, like for Q clips, search for "Yakima Q38" and try different combinations of search terms.

Remember that towers and clips need to be an exact match, but crossbar lengths are a recommendation, usually the minimum. My Xterra showed up as needing 48" bars, which turned out to be the shortest option, but I could also have gotten much longer bars if I needed to for a canoe or something. Legally they can't be wider than the widest point of the vehicle, but I've seen Toyota Corollas with two canoes on the roof, dwarfing the width of the Corolla.

Good luck.

Thanks!

http://greenhybrid.com/compare/mileage/car/3686.html

http://greenhybrid.com/compare/mileage/car/4955.html