MobilTrak says its next-generation DSP technology can track listening for more autos. It claims the technology, in development for three years, allows it to offer users "substantially" increased sample sizes. The new technology, Centatron DSP, monitors all commercial radio frequencies simultaneously, and can track multiple vehicles tuned to the same station, based upon differences in the digital "signatures" of the tuners being detected. The company says it can sample virtually all vehicles passing a measurement site that are tuned to a radio station. For those drivers who have privacy concerns, the company says the signals detected cannot be tracked to individual vehicles.