This also depends on the project completing as planned. Borconi-Szdressy is close to hitting his funding target and expects the first dongles to ship in December for $55 each, but there’s always the possibility of delays or other setbacks. You’re backing the project in hopes of getting something in return, not making a pre-order.
Still, this could make Android Auto considerably more practical if you’re willing to take a risk. You might not have to be quite so picky when shopping for a car or head unit. This could be helpful if you’re using an older phone, too. AAWireless only needs a phone running Android 9 Pie, so this might help you delay a device upgrade if wire-free Android Auto is important.