Can anyone advise please. My L322 TDV8 2007, has developed an intermittent fault whereby when starting off the sat nav/ entertainment screen goes off. When I finish my journey and turn off the ignition and remove the key it does not make the usual mechanical switching sound and when I open the door a warning chime sounds and I have the message "Key in ignition" but it isn't. The car will not then lock remotely I have to do it manually. Any attempt to restart the car will not work until a period of time has passed when it appears to reset itself. A new ignition switch has been fitted, all terminals appear tight. Any advice would be welcome. Thanks.