Today, Automatic Labs launched an update to the iOS version of the app that works with the company’s $99 vehicle diagnostics dongle that enables Ford drivers with SYNC to use Siri hands-free. Ford hasn’t issued any release about this and Automatic’s blog post is sparse on technical details so I reached out to Ford technology spokeswoman Emily Olin for some details.

First a bit of background on Automatic Labs. In 2012, they launched an app and accompanying bluetooth adapter that plugs into the OBD-II diagnostic port that is built into every new vehicle built since 1996. The app is free and an Android version is also now available but, the adapter $99.

When plugged in, the dongle reads data off the vehicle’s internal communications network just like the diagnostic tools used by technicians at every dealership service department or local garage. The app gets the data and can display all kinds of useful information for drivers such as fuel economy, diagnostic faults and tell you how much you are spending on fuel and how efficiently you are driving. If can even call 911 when an airbag deployed message comes across the network.

The latest trick that Automatic has added with some help from Ford is to read voice commands off the network. When the driver presses the voice command on the steering wheel while the automatic adapter is plugged in, the commands are transmitted to a connect iPhone where the Automatic app then passes them along to Siri for recognition and execution.

According to Olin, no upgrades are required on the vehicle, just the addition of the Automatic adapter. Automatic’s website mentions that an Android update is also forthcoming that will presumably pass the messages to Google Now.

At $99 for the Automatic Labs adapter, you’ll have to decide if Siri in the car is that important to you. However, the upside is that you can use it with existing cars with SYNC and you won’t have to spend tens of thousands on a new car with Siri Eyes-free or CarPlay.