Sure, we've seen Siri used to do a host of things, including controlling the temperature in a hacker's home. But the folks over at Autoblog were curious to know just how well the virtual assistant would work with Bluetooth-enabled car stereos. Once your iPhone 4S is properly tethered, holding down the handset's home button will activate Siri. Treating her as an incoming call, your Notorious B.I.G. playlist will pause before the ready-for-command chime sounds. The in-car assistant was tested on two Mercedes-Benz automobiles, a Chrysler 300, a Dodge Charger and a Nissan Maxima, with the Maxima showcasing the best results. It comes as no surprise that mic placement on each stereo and in-cabin background noise provided a noticeable difference in Siri's listening abilities during the test. For a glimpse of the action before trying it out yourself, hit the video just past the break.