A car hands-free unit (HFU 140) with a Low-Power Radio-Frequency (LPRF) module 141 (typically a Bluetooth module) configured to receive an identifier 134 from a car key 133. Different drivers are provided with different car keys 133. When receiving the identifier 134 first time, the HFU stores trusted data to pair with a driver's phone. Thereafter, the HFU automatically connects to the driver's phone when the same car key 133 is used. The hands-free unit typically comprises a microphone and a loudspeaker, and can also have a display and/or a camera. In operation the HFU provides automatic link 160 with a compliant LPRF enabled mobile phone without need to touch the mobile phone, allowing its use even when the mobile phone is placed in a boot of a car 101.