This rugged and waterproof one is a pretty sweet bluetooth speaker, and can go anywhere including your dashboard for speakerphone. It's rugged specced with real protection (real rubber shock absorption etc); it's waterproof, floats, and has great battery life and sound.

I took a chance and got one a while back, it works very well and sounds pretty incredible considering its size and versatility, just keep it a step below full power and out of direct sun to keep your speakers crisp. After a year mine slightly clip on full blast, that's the only degradation after a year of abuse, both with direct sun and full blast (used it to practice/jam with often in puerto rico sun, full volume is usually too loud for inside music listening, even outside within a certain proximity).

Anyway, one step below full volume is still very loud and sounds same as it did out of the box; I use mine daily.