Yes, there are ways to add Android Auto to an older car that originally does not have Android Auto built-in.
A common option is to use an Android Auto dongle or adapter. These devices connect to the existing head unit and provide Android Auto functionality. They usually connect via USB and allow you to mirror your Android smartphone's screen onto the car's display, providing access to Android Auto apps and features.
Another option is to install an aftermarket head unit that supports Android Auto. These head units replace the existing car stereo and offer Android Auto compatibility along with other features. They typically have a touchscreen display, support for smartphone connectivity, and provide access to Android Auto functions.
If you're interested in using Android Auto Wirelessly in your old car and already got a existing head unit, consider an AAWireless device for your car. You can find it on our webshop (Europe) or on platforms like Amazon (UK&US). However, please note that it is recommended to verify the compatibility of AAWireless with your car before making a purchase.