Something like this - http://www.ebay.com/itm/CX919-RK3188...item3a94c93d2b
Quad core, comes with Jelly Bean, there are custom ROM's out there to install KitKat on it, has BT and WiFi, 1 full-size USB port, USB host mode, and it even has a MicroSD slot for datalog storage. Should work and it's only $45.
Need to find a 12v-to-5v power supply to run it from the car.