1-Wire RFID readers are excellent for these use cases:

Immobilizer: prevents anyone from starting the vehicle without first scanning an iButton.
Authorized Driving: keep track of who is driving your vehicle based on the iButton ID they use to authenticate.
AutoGeofencing: lets you know when the car leaves customized areas without iButton authorization.

Features

• 1-wire interface
• Wiring - White wire - 1-wire data, Brown wire - power, Green - ground
• Power supply - 6.5-30 V DC
• Frequency standard - 125 kHz
• Transponder type - Manchester, 64 cycles per bit
• Antenna surface - 6.8 cm²
• Reading range - 4 cm
• Reading frequency: 6 times per second for identification, 2 times per second when the transponder is within reader range
• Supported 1-Wire commands - 0x33 (0x0F) - Read ROM, 0xF0 - Search ROM
• Cable length 40 cm
• Operating temperature -20 ºC to +55 ºC
• Operating humidity Up to 70%