This is essentially a 7" display which your phone can connect to via Bluetooth. The display then mounts on top of the dashboard and can be interacted with, as if you had CarPlay or Android Auto on your car's head unit.
It will, by default, use it's built-in speaker for sound output, but it also has an FM transmitter so that the audio can play through your car speakers (will work if your radio is so old it does not have Bluetooth, but audio may not be great). Otherwise, if your car head unit has an AUX input, you can connect a cable to that.
It's by no means perfect, as can be seen from the review, but it is an option worth considering if there is nothing else.
Why not just use your phone on a holder? Well the screen is a bit bigger, orientation is correct, and more importantly CarPlay and Android Auto are optimised for minimal touch operation vs a phone screen interface.
See Intellidash Pro is an easy way to get CarPlay in older vehicles | Engadget
It's not the prettiest thing to sit on your dashboard, however..