chemical additives for vehicle air conditioning systems; chemical additives containing chemical refrigerants used to increase performance of vehicle air conditioning systems; chemical additives for vehicle air conditioning systems sold in pressurized cans; chemical additives for preventing and stopping leaks in vehicle air conditioning systems; chemical additives for improving durability of vehicle air conditioning components; chemical additives for lubricating vehicle air conditioning systems [ ; and chemical additives for quieting vehicle air conditioner compressors ]