According to Jalopnik, the press release eloquently describes the speakers:
Stuttgart. On the racetrack, the sound of the of the Porsche 911 GT3 exhaust system is unmistakable. So is the tailpipe cover of the sports car, which is equally distinctive and is now more than just a functional element – it’s also a design feature. Porsche Design has taken the imposing rear aspect of the 911 GT3 and used the original tailpipe cover as the main part of its new Bluetooth® 911 Speaker. The result: maximum power and sound, as impressive as the engine sound on the track. An absolute must-have for music and sports car enthusiasts.
In the description, it says that the speakers use the original tailpipe cover, which is just a flat out lie. You can tell just by looking at the speakers that it's just a cheap, plastic outer shell. I have no idea what the sound quality of these speakers is like, but it isn't worth $550. It might be worth like $40, but I can't imagine anybody going in and spending that much money on speakers, unless of course, they need everybody in the world to know how much better their Porsche is than whatever crap car you drive.