Air con stopped working - system was re-gassed and working again, but still getting noise from behind the dashboard which sounds like the evaporator or valve groaning! Stops as soon as you switch off air con and noise is louder when on the move versus engine idling. Has anyone else had, or is having, similar groaning from their system and found out what it is??!! Also, perhaps a poll on the price for a re-gas would be useful - mine was