Where is the port to add freon on a 2003 BMW X5?

On a 2003 BMW X5, the port to add freon (refrigerant) is located on the low-pressure side of the air conditioning system. You can typically find it near the accumulator or receiver-dryer, which is on the driver's side of the engine bay. The port is usually a smaller fitting compared to the high-pressure side port, which is larger and typically located near the compressor. Always ensure the system is off and follow proper procedures when handling refrigerant.