Found this product, input voltage 12v - 24v, outputs 5v through a USB socket.
Here’s the description :
"The single port USB charger for car cigar/cigarette lighter allows users to charge their USB devices, without the need to connect the device to a computer. This product is compatible with most devices, including mobiles phones, most MP3 players & satellite navigation products.
1000mA power is much higher than standard adapters can supply so works with nearly all USB power devices.
- Input Voltage: DC 12-24V - Output Current: 1000mA (+/- 50mA) - Output Voltage: DC 5.0V"
Will the 5v output be sufficient to power Fez board + gps etc…???