Just placed my order and was invited to configure. I am curious about a couple of packages. Specifically am wondering: * Is the audio upgrade worth the $$$? I love my music and have in the past ordered very expensive sound systems in cars as well as put in aftermarket systems. I have the audio upgrade in my Model S but I don't find the system to be very good in terms of audio quality. I'm wondering if I could save the $$$ and get a Reus system installed without having to spend the initial $2500? * Is there any ambient lighting if you do not order the premium upgrades package? * How good are the ventilated seats? Do they cause any issues? * The pictures show the Alcantara headliner in the design studio, even if I have premium package deselected. Does this come without the premium package?