Google has enabled cord-free Android Auto in vehicles that have an Android Auto Wireless-compatible infotainment system (built-in or aftermarket), but only if you have a relatively recent Google phone running Oreo – that means a Pixel, Pixel 2, Nexus 5X or Nexus 6P. Sorry, folks, your LG- or Samsung-branded phone will have to wait. You'll also need a USB cable for the initial setup, so don't leave the wire at home the first time around.
Wireless, smartphone-based in-car interfaces have been slow in coming regardless of which smartphone you use. Apple's CarPlay has supported wireless connections for longer, but it's still not nearly as common as its wired counterpart. Still, this is an important step. Car manufacturers and electronics companies may be more likely to add wireless support knowing that there's a wider variety of compatible handsets.