I have a 2009 335i Sedan which has the tire pressure sensors. It appears that the only readout from them is a warning if a tire gets 25% low. I'd like to be able to see the actual pressures and temps so I can see a slow leak coming or diagnose a failing tire. Does anyone know if there is a way to compel the car to show the actual pressures and temperatures on the iDrive or trip computer? Has anyone tried using an aftermarket TPMS receiver to read the pressures?