There is a video going around showing Slate’s answer is an optional, removable Bluetooth speaker. It looked similar to a JBL. There’s a bracket to mount it on the dash.

I'd rather have my Bluetooth speaker stolen than an installed stereo stolen where they just gut parts of the car and rip things up. But it will be a bigger target since it's easier to resell.

Looks like the dash and door cards are pretty much just flat plas- er, reinforced polymer. Aftermarket stereos and speakers come with mounting brackets and bezels to cover the holes you’ll need to cut.

just place 4 bluetooth speakers connected to eachother in a mesh or something