And I am going to tell you why. Now, you may wish to revoke my man card after this post, but I assure you, hear me out before you go on and call for my head.
Besides the obvious reason of good fuel economy, the prius makes its self the best road trip car for a few more, less thought of reasons.
1) You can fit a twin sized futon mattress in the back with the seats folded down. True story. Fold the front seat backs up a bit, and lay the rear seats down, and you have a full beige bedroom at your disposal. While driving, just bend the mattress up behind the front seats, and you have room for your luggage on top of the mattress. Outside of a pontiac aztek with its goofy tent there is no better option out there that will return decent fuel mileage.
2) Climate control. Yes Climate control. What is the worst part about sleeping in a car? Its getting cold or hot at night, making sleep difficult. Well, with the prius you can leave the car on all evening running the climate control systems and barely use a few sips of fuel. The system will run off of the battery, and kick on the motor occasionally to keep charging.
3) Ride Quality. Lets face it, the prius may not be rolls royce levels of comfort, but its not bad in any way shape or form. The seats are comfortable, nicely adjustable, and the interior, while bland is nicely appointed. You get a nice upright, high seating position and a fishbowl of glass to see out of the entire car.
4) Performance. Lets face it, if you're road tripping, you're going to be going around 70 mph the entire time, needing just a little juice to pass. While the prius isn't setting any land speed records, when you tell it to move it will do so happily.
5) Blendability. Lets face it, unless you are doing some face melting speeds, the Law enforcement you encounter on the trip are not going to think twice about the beige box scooting down the road. Instead they're going to be pulling over that dipshit in the v6 mustang who cut you off 2 miles ago and is weaving in and out of traffic.
6) Fuel savings. The prius is so efficient you can tour the entire USA, while sleeping in your car, for approx $500. Thats a cheap vacation any where the road will take you.
Other positives include large hatch area to profess your love for things via bumper sticker, The troll factor (pissing off everyone else on the road, just because your in a prius), and the economy gauge, which provides hours of entertainment trying to get the best numbers possible.
Ok, now you may rage against me, revoke my gear head card, and burn me at the stake. Fact of the matter is the prius is an excellent road trip car. Used examples are getting cheap, and while I would rather stay at the Ritz and drive an e39 m5 through out the USA, the prius is better suited to those on a budget. So, round up the socially awkward kid in your dorm who drives their parents old prius, or take your parents prius, or your grandmothers aunts cousins prius, and go out and see what our beautiful country has to offer. But wait a few weeks, because due to the govt, all of the places you really want to see are closed.