Your car and house may soon be having conversations about your whereabouts, thanks to a new feature from Automatic's car tracker. The $100 dongle (US only) -- which attaches to your car's ODB-II port to track your driving and save fuel -- now works with Nest's thermostat to optimize home heating and power usage. The system allows you to create basic "rules" that can switch Nest into home or away mode, depending on your whereabouts. It also supports deeper functionality, that could, say, crank the heat when you pass a certain landmark on a specific day. The systems will supposedly work together to learn your habits with the goal of eventually giving you "just-in-time" heating control to minimize energy usage. Or, you know, plot your overthrow.