An older car doesn't need a completely new sound system just because it was built before Bluetooth, CarPlay and Android Auto became common. If the radio and speakers still sound fine, you may only need a small adapter to enjoy music from your phone. Plus, a portable dashboard display can add navigation and other phone controls without replacing the factory stereo.

The right upgrade depends on what's missing. If you just want wireless music or podcasts, start with the connection between your phone and the stereo. If you want maps, calls and messages on a screen, a portable CarPlay or Android Auto display is a bigger step.

Replacing the head unit makes more sense when you want those features permanently installed.