Not sure if there is another thread about this. I am contacting Reus Audio for upgrading my stereo system. They are based in Orange Country but travel to the SF Bay Area frequently. At present, their mid-tier system for Model S costs around $4K and a group buy (5 and above) will enable a ~$500 discount per car. They can work with cars with or without UHFS. They will come to your place for installation/tuning, which typically takes 5-6 hours. If anyone in the SF Bay Area is interested, please reply in this thread and/or PM me.