Winnebago Macerator Pump issues

Best macerator pump system I ever had was in a 1972 "Leisure Lodge". It had the regular gravity dump (one tank for both grey and black water back then) but also had the macerator. It had a control module that had a driveshaft speed sensor and a temperature sensor clamped to the radiator hose. When speed reached 40 and temperature was greater than 175, the pump would start and the sewage was injected into the exhaust pipe right behind the manifold. I don't remember ever having to connect the sewer hose. Always wondered if people driving behind us noticed anything......