Is there anyone that still does Head Unit Firmware upgrades?!
 

According to what I've found by searching the one company that used to do firmware upgrades for $50 is now MIA and all the links to the service are dead.

Are there any new developments in this or anyone else that can do a 9.55 upgrade?

Not that I am aware of, but you can get a later model head unit for cheap.

www.revvinsevens.com
www.partsgroup.com
www.mazmart.com

I couldn't find any info on VIN cutoffs for firmware revisions .. is there a set model year where 9.55/9.6X should be available? Have to ask since many of them are already removed from the cars and the people can't get me the Firmware version :\

My car that was delivered in November 2003 has already the firmware version 9.55 - hope that helps somewhat.

Well, my 2004 Touring is below the 9.55, which is why I bought the factory ipod connector. I am in possession of Hoss-05's 2005 Rx-8 and I just checked and his is 9.73. So I would say anything 2005+ would be good.