Add line for onboard nav system

I have a By the Gig account. Will I be able to add a line to use in an Android (not Android Auto) head unit for my car? It's a 4G mobile device that takes a Micro-SIM card, just like a phone or tablet, so it should be compatible. The question is whether Xfinity will support it? I don't have it yet, so I don't have an IMEI number to try with Xfinity's online compatibility tool. Has anyone gone through this procedure with Xfinity Mobile?