I am told by my car shop that freon for my Rolls Royce Silver Shadow II is no longer being made/sold. The shop says that the Silver Shadow II radiator/coolant system is being converted and I have to change it out. Do you have any other suggestions other than replacing the unit? Also, it is normal for the car to run really hot. The floor in the drivers area gets HOT!! I drive with the windows open until the situation with the ac/coolant system is resolved. Thanks for any insight.