We designed, constructed, and evaluated a mobile medical care vehicle called "Rollende Arztpraxis" (rolling medical practice, RMP) that delivers the full medical care of a general practitioner to increase medical care supply in rural areas. Six communities have been identified, where the RMP has been visited 501 times in 14 months. Two different schedules of stops and treatment times have been tested. We show that the RMP treated mainly elderly and multimorbid patients. An accompanying study showed high acceptance and satisfaction of treated patients and treating doctors. An economic evaluation of three different utilization models with three treatment modes each showed no financial sustainability. We show that ambulatory care in rural areas can be complemented by a mobile care unit, if legal and financial barriers can be overcome.