My 400E has undergone a major repair. The entire cooling system has been replaced by my local MB dealer to include a new condenser. My car runs hot while at traffic lights and never cools unless I am driving 75 mph. The dealer has stated that the repair was done correctly, however I am upset about the discomfort the A/C system in my car is providing in the 80 and 90 degree days in Maryland. Any suggetsions?