the way i read the california code is that back fees constitute a lein on the vehicle. this allows them to take the car from you if they catch you driving it. and yet, there's a few catch phrases like that says after five years, a perfected (documented) lein is dropped.
i'd ask dmv.
seems the director is the only one that can make the choice (because i guess someone gave them the power to do it.) [xo's guess: it's $250 + registration, transfer fees and i bet they'll make you smog & certify it with the new laws they are trying to enact.]
http://leginfo.legislature.ca.gov/faces/codes_displayexpandedbranch.xhtml?tocCode=VEH&division=3.&title=&part=&chapter=&article= chapter 6 article 6 9000.
my question to them would be is if you paid an extra $9500 to register it in california. is the car worth the extra $9500 now and you have to pay extra california sales tax on top of the sales tax for parts you paid out of the original $9500. they don't answer that question either.