For me, the requirement comes down to a base framework and module that supports:

What is interesting is the advent of low-cost Linux frameworks that are very close to what we need. Things like the BeagleBone and RasberryPi are fascinating, but really designed for HDMI video output - and the overhead of GPU + HDMI is a huge power drain. The closest I've found to what we require is (http://compulab.co.il/products/computer-on-modules/cm-t335/) - pretty amazing little device - low power, wifi+bluetooth, dual CAN, up to 512MB RAM and 1GB FLASH, for around US$50 (in horrendous quantities). I'm working with my contacts in China to see if we can base on a dev board something like that. If they can make Android phones for US$50, we should be able to get the guts of such a device for something similar. Then, add on GSM, take it from a BOM to a product, and we're probably looking at something still <US$150 but with so much more. The closest thing to ideal I've found at the moment is build a baseboard (connectors, power, CAN buses, etc) and have slots to take that CM-T335 module and an optional GSM module. But, I still think we can find something on the China market even closer to what we want/need.