To Each and ALL Amateur Radio operators in the State of California
As a Citizen and Radio Amateur it is your responsibility to contact your Assemblyman for the State of California requesting that the Department of Motor Vehicles desist in placing spaces on our Amateur Radio license plates. This is a minor software fix and does not comply with the Vehicle Code described below. My thanks go to Pam W6PNW on her research.

You may say to yourself, well I already have plates on my car. If you should buy a new car or try to transfer your plates to another car, you will be asked to surrender those plates and the DMV will issue you new plates with a space after the number in your Callsign. If you haven’t heard about this, you are now. Please take the time to view some of the websites; SEE http://kg6sblog.calsage.com for updated information of Reversed decision by DMV.

Send this to your Assemblyman also: Sample letters on http://nospacehamplates.blogspot.com/ or http://kg6s.calsage.com
California Vehicle Code section that applies to amateur radio license plates, Vehicle Code Section 5005:

5005.  (a) Any person holding an unexpired amateur radio station
license issued by the Federal Communications Commission may, after
the requirements for the registration of the motor vehicle have been
complied with, also apply directly to the department for special
license plates, and the department may issue special plates in lieu
of the regular license plates.  The special license plates shall be
affixed to the motor vehicle for which registration is sought and, in
lieu of the numbers otherwise prescribed by law, shall display the
official amateur radio station call letters of the applicant as
assigned by the Federal Communications Commission.
   The applicant shall, by satisfactory proof, show that he or she is
the holder of an unexpired license.
   (b) The department shall not issue more than one set of special
plates for any licensed amateur radio station.
   (c) In addition to the regular fees for an original registration
or renewal of registration, the following special fees shall be paid:

   (1) Twenty dollars ($20) for the initial issuance of the special
plate.
   (2) Twelve dollars ($12) for the transfer of the special plates to
another motor vehicle.

Please note the phrase which I highlighted in yellow:  "as assigned by the Federal Communications Commission."  The FCC does not assign "call letters" (call signs) with spaces.  Period.

There is no ambiguity in the wording of the statute. Therefore, any "regulation" adopted by the DMV that contradicts this "statute" is trumped by the statute.

For the non-lawyers in the group:  a constitution trumps a statute (a law passed by the legislative representatives of the voters), and a statute trumps a regulation or rule (adopted by appointees of the governor or appointees of a legislative committee or employees of a state department or state board or agency).  Why?  The last group, (the DMV, its appointed head or hired employees), have less accountability to The People. Our legislative representatives have more accountability -- and The People had a chance to have some say in the content of the statute before it was passed; but we generally have no say in the adoption of regulations.
Notice that the verb "shall" occurs before the phrase I highlighted in yellow in the statute.

In the law, "shall" in mandatory.  The DMV has no discretion.  "May" would have left them some wiggle-room.  "Shall" does not.
This research was done by Pamela Royce W6PNW, ESQ – Kudos Pam! (Who also was spaced on her plates)