The big problem is that you have no way of knowing if the pressure/temperature that is being shown is current, or from an hour ago. While traveling, if the monitor loses contact with the sensor, when do you find out? The consensus is that it could be an hour or more. The does not give one a reliable status of your current conditions.
After I've been on the road for about an hour the pressures and temperatures tend to stay pretty steady without much change. And I don't look at the monitor that often, since I rely on the alert to notify me of an issue. I don't need another device taking my attention away from my driving.