Sophisticated automobile technology makes high-performance engines purr in relative silence, but automakers fear that their most demanding drivers are emotionally attached to the engines' roar. Consequently, as Car and Driver reported in April, the 2012 BMW M5, with 560 horsepower tempered with sound deadeners, has installed pre-recorded engine noise, channeled into the car's cabin via the stereo system. A computer program matches the amplitude of the engine's growl to the driver's accelerator-revving. In other automobile tech news, Peugeot technicians announced in March that they were preparing "mood paint" for the body of the company's iconic RCZ model. The paint's molecular structure would be alterable by heat sensors in the steering wheel and elsewhere that measure a driver's stress levels. A calm driver might see his car turn green, for instance -- but watch out for road-rage red! [Car and Driver, April 2012 (not online)] [DieselCarOnline (Leamington Spa, England), 3-31-2012]
