Well since November 09 I have been wrangling to get this fixed. Yesterday I finally got a new head unit fitted. Here are the excuses I had from Chrysler MAIN Dealers here in the uk -

1 -There is nothing wrong with it they just arnt that accurate due to the discs being out of date!
2 -We cant souce any new ones as they do not stock them anymore, but we have ordered one and we will let you know when it comes in - Nothing heard
3 -We have one come in and we will fit it - woops sorry it has the wrong colour buttons black not silver
4 -The sensor/receiver is worn/damaged and this is wear and tear and could have been damaged and therefore its not covered by warrenty
5 - The windscreen is a replacement one and the signals can not go through it as it is not genuine Chrysler
6 - its a £1500 fix and it would not be covered on the warrenty

Eventually thanks to this site again I managed to show that 1 the sensor/receiver was fine and was picking up all the signals therefore was not worn out and the windscreen was not stopping the signals, also my step father who is a parts manager for Toyota confirmed that considering all the windows have the same mark on them it is more than likely it is orignal or Chrysler as otherwise it would be different.

I then took the car in and showed them the signals were being recieved, told them to get a new head unit and if it does not work due to any of the above I will break the windscreen and get a genuine replacement on insurance. Also there are up to date discs 2.2 version that ought to be fairly accurate for here and all of Europe from 2006 ish.

Well there you have it needless to say I finally had it fixed by a Mecedes Benz dealer who honoured the warrenty and fixed it in just 1 week. The warrenty ran out yesterday on the car he looked it over changed the gaskets on the rocker boxes again as the previous Chrysler dealer made a hash of them and Im a happy chappy!!