Is there any tablet/large phone that can pair with another phone via bluetooth as a headset?

[AC Question]

I'm looking to replicate a car's navigation system with my android phone and tablet. What I want to do is use a tablet (7" or so) or a large phone without service (i.e. Galaxy Note) to mount to my older car's dash so I can use my GPS app (doesn't require data) but also when I get a call to the phone in my pocket, the screen indicates as such and lets me press a button to answer and start talking...just like a phone's nav system does.

 

[B. Diddy]

Welcome to Android Central! The closest I can think of is LG's QPair feature, which essentially tethers a tablet to a phone: A quick look at receiving a phone call on the LG G Pad 8.3 | Android Central. I'm not sure if you have to use LG devices in order to get the full functionality (i.e., being able to answer a call with the tablet instead of the phone).