7.) How do I obtain proof of correction?
Corrections for most mechanical violations can be inspected by the Sheriff, California Highway Patrol, the Department of Motor Vehicles, or other approved law enforcement agencies. You must also pay a $10 transaction fee per Vehicle Code section 40611(a).
Proof of correction by an authorized law enforcement agency is to include:
· Inspecting officer's signature and printed name
· Badge number
· Registration and License Violations
· Submit the proof of correction by having the police officer inspect your
vehicle and validate your ticket.
If you were cited with a registration violation and have proof of valid registration from the DMV, you may submit a copy of your registration with the appropriate bail to the Court.
If you cannot provide proof for the vehicle cited, you will be required to pay the bail associated with that violation or appear in court.
Some violations, including, but not limited to, sections 12500, 14601, and 23109 of the vehicle Code may require a mandatory court appearance. Contact the Court for further information
LINK:
http://www.santacruzcourt.org/Traffic/FAQ.htm#7
Basically you're assed out. Your shit wasn't registered the time you got your ticket and you neglected to get the car registered and now its no longer in your ownership. Pay the $300 and keep it moving because there is no way you can show proof of registration now. I'm assuming that $300 is the bail amount.