I am extremellllyyyy underwhelmed by the standard audio system in the Tesla. My mom's C300 blows it out of the water, and even my friend's new Hyundai sounds 5x better. Tesla's standard audio system sounds flat, does not fill the cabin, and completely lacks bass IMO. I've tried all sorts of audio formats (not just the compressed Internet audio), and I still think it's underwhelming. This is the only thing I've been disappointed about after shelling out close to $100k for a car, where cars 1/4th the cost outperform it. That said... 1) What upgrades have people done to the stock sound system, and 2) What was the cost of your upgrade? I really didn't want to shell out the $2500 for improved audio. I know I've seen a few threads about people upgrading to Reus audio systems, but that's just as expensive. I've also seen more small scale upgrades where the author's admit the improvement to be very small. I would love to hear what others have done to improve sound. I believe there is an "empty" spot for another speaker on the rear trunk for those without the sound studio to put something. Thanks all.