Links from the National Lightning Safety Institute and a couple of others. Lots of reading, good info and with lighting, you shouldn't fool around...
Vehicles and LightningLightning Safety for Campers and HikersLightning Protection: New Myths & Old RealitiesLittle Known Lightning InformationPersonal Lightning SafetyUS Scouts - Lightning Safety Rules and TipsNOAA Lightning Resource Page
Summary- Best to get into a metal vehicle, such as your truck or car, NOT a fiberglass vehicle(such as Corvette, Saturn, etc.)and NOT a convertible...
In your RV, don't hook up to anything-especially the electric, stay inside and don't touch anything metal...
Probably more info than you wanted, however I hope that it helps!