Million Mile Road Trip - Rudy Rucker

When a seemingly-innocent trumpet solo somehow opens a transdimensional connection to Mappyworld, a parallel universe containing a single, endless plain divided by ridges into basin-like worlds, three California teens find themselves taken on a million mile road trip across a landscape of alien civilizations in a beat-up, purple 80s wagon . . . with a dark-energy motor, graphene tires and quantum shocks, of course. Their goal? To stop carnivorous flying saucers from invading Earth. And, just maybe, to find love along the way.