I drive an old Japanese kei truck that only has an AM radio. There isn't a great way to replace the stereo, which makes a bluetooth speaker my best bet for music and navigation. This seems like a great place to look for a recommendation for a speaker, given the unique requirements:
It has to sound good at high volume
The truck is pretty loud, especially at higher speeds
It has to have accessible power and volume buttons
The speaker will sit in a recess on the dashboard, and would ideally have buttons that aren't on the back or underside. I'd like to be able to easily reduce volume at stop lights and easily turn it on when I get in.
It can't be cylindrical
Or at least it has to sit flat with those buttons on top. My current speaker is a cylinder and rolls back and forth in its perch on the dashboard. It will sit in a recess, so it doesn't need to be super grippy or anything, it just needs to have a flat "bottom"