This is likely Otherworld, as per Identification of mid-80s time travel tv show.
In the first episode, the Sterling family (Hal, June, Trace, Gina, Smith) take a tour of the interior of the Great Pyramid of Giza at the same time as a once-in-ten-thousand-years conjunction of the planets. Inside, they are abandoned by their guide, and as they try to get out, they are mysteriously transported to another planet which may or may not be in a parallel universe.
On this other planet (called 'Thel'), which is inhabited by humans, there are no familiar countries or states. The area they are in is divided up into self-contained "Zones," each with a wildly different style of government and way of life, although the province of "Imar" (ruled by a Praetor) appears to be the central seat of government for this entire Earth. Most of Thel's history is not revealed, although the pilot episode contains references to 'territories', android creators, and 'wars of unification'. It is thus unknown whether Thel is an alternate universe version of Earth, or another planet entirely.
Travel between Zones is so strictly regulated to the point that no one can travel outside their home zone province (save for the Zone troopers), and all maps have been banned by the state. Thus, the inhabitants of each zone know absolutely nothing about life in other areas. The family could not know about the travel ban, and approach a soldier (the first Thel native they met) in all innocence, seeking help, while the soldier - Kommander Nuveen Kroll, reputed to be the worst, and most ill-tempered of all Zone Troopers - views them as lawbreakers and treats them as such. When Hal insists they need help, Kroll attempts to arrest them and gets rough with Smith, the youngest of the Sterling sons. The Sterlings resist and, in the struggle, Kroll's sidearm weapon goes off, and the ricocheting laserblast renders Kroll unconscious. The Sterlings take his access crystal, (which is possessed only by Zone Trooper officers, and which gives them security access to state-controlled equipment and information data banks) his vehicle, and his sidearm and drive away. For the rest of the series, Kroll is resolute in his attempts to recover his crystal, capture the Sterlings (whom, in a report to his superior, he would later regard as a band of "armed terrorists") and subject them to severe punishment.
There's no RV involved, with the Sterlings starting the first episode in Egypt, meeting the tour guide who takes them to the pyramid, but as Valorum notes, Kroll's vehicle might be what you're remembering.
The Opening of the Show