Pratz, a former race car driver, said the system has been tested at -- and well above -- normal highway speeds.

"I was with a partner and we were going 120 miles per hour and it worked just fine," Pratz laughed. "[My partner] didn't like it too much, though. He was running a network test and looked up and saw that it was working well but let me know he didn't like going that fast."

The system doesn't have trouble when it detects other Wi-Fi networks, Pratz said.

"We've gone down 19th Avenue in San Francisco, which is lined with homes," Pratz said. "We'd do our tests, and the computer would pick up 50 or 60 networks, but it always stayed with Autonet. It's the intensity of the Wi-Fi in the car that does it -- your device is never more than five feet away."

And besides, he noted, even if there was interference, you could set the Autonet network to be the preferred network.