[drswong]

I read from wiki and other websites saying that BMW cars with comfort access are vulnerable for being stolen using OBD.

What shall we do to minimise the risk?

Theft using OBD

In 2012 BMW vehicles were stolen by programming a blank key fob to start the car through the on-board diagnostics (OBD) connection.The primary causes of this vulnerability lie in the lack of appropriate authentication and authorization in the OBD specifications, which rely largely on security through obscurity.

From Wikipedia.