I found some very interesting information in the empeg-car forum. Apparently, someone very skilled with a soldering iron was able to add ram to an empeg. There's also a "piggy-back memory upgrade" technique that I have seen references to. I think this means that it's possible to upgrade to 16*4 = 64.

Check out the thread and the picture...
http://empegbbs.com/ubbthreads/showflat....true#Post251045