How can the a/c be improved? My question is why do these 240 Volvos have poor a/c? What is so hard or complex about producing a good and efficient A/c? What can I do to improve my a/c? On hot days it does a poor job of cooling the car. I recently changed from freon to 134A and on a few hot days the car nearly overheated with the a/c on. I had to shut it off and put on the heater. What can be going wronh here, and any suggestions as to what i can do about it?