Hi Marc, congrats on the E53 👍
You don’t need to replace the whole radio.
On the BMW X5 (E53) with 4:3 nav, you can retrofit Bluetooth in two main ways:
OEM solution - retrofit a factory Bluetooth module (ULF) if the car is pre-wired. This keeps the original look and integrates with the screen and steering wheel buttons.
Aftermarket interface - install a Bluetooth adapter (e.g. GROM/Dension) connected in place of the CD changer. This is easier and more modern.
If you want OEM look → go factory retrofit.
If you want simple and reliable → go aftermarket interface.
monkey mar