If you connect to your personal wifi network when parked at home, you can probably see the MAC addresses for all devices (including the FFE) somewhere in your router/AP admin page.
Btw, the IP address assigned to the car (by your router/AP) when connected to your personal wifi network will mean nothing on your work network. On your work network, the car will be assigned a completely different IP address. The MAC address (built-into/configured to the car's wifi radio) is what you want.
2013 FFE, Platinum White, Delivered January 2013
2017 MS, Midnight Silver Metallic, Delivered February 2017
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