Has anyone found wireless, rechargeable, bluetooth speakers that are loud enough to listen to music at highway speeds? I'm looking for something (preferably small) that I can mount to the top of my dashboard that will connect wirelessly with my iphone. I am looking at the Ultimate Ears Mini Boombox, but I'm not sure it will be loud enough. No information on the wattage of the speakers. Wondering if anyone has found something that works.