So adventure = expedition? Well, this is not an expedition (per say) event. It's a 7-day trip ranging anywhere from 1,500 - 2,500 miles of non-stop movement though. You have to remember that the terrain they make you go through is extremely aggressive, not only does your rig have to make it through a long day of extreme abuse (sometimes starting early morning and not ending until late at night), but it also has to be in proper working order by around 6:00 AM the next morning to drive 300-700 miles to the next spot. In between all the fun trying to keep your vehicle together, you have to provide your own food while camping in the middle of nowhere, and any other essentials you may need.
An you are correct, "most" of the vehicles are not set up for long range and are more like undercover (or not) rock/race buggies. Mine is probably the most set up for expedition, so I had more of a challenge in the super aggressive terrain than the comp guys........but we were comfortable and didn't have to stop every 150 miles for fuel either. A lot of the rigs are trailered to the starting point and trailered home from the finish, some are not. In 2008 we put over 4,600 miles on our truck in 7 days (very, very hard miles), this year was 2,500 since it was on the right side of the country for us. Keep in mind this is my daily driver that gets me t work everyday also.
Expedition, probably not.........extremely difficult triathlon is more like it......