A while ago, my Mom, who lives in Massachusetts, gave her car to my
wife and me.  She signed over the Massachusetts title to us.  We've
never registered the car, nor gotten a California title.  We'd like to
sell it, and are wondering what we need to do with the DMV to make
this legal.

Hi earthman,

Here you go - this should keep you busy for awhile! I investigated
just transferring the ownership between family members, but that can
only happen if the car is already registerd in California.

Transfer a Vehicle Between Family Members
When the Department of Motor Vehicles (DMV) talks about "transfer," we
mean a change in the registered or legal ownership of a California
registered vehicle. When a vehicle changes owners, whether by sale,
gift, inheritance, etc., and the new owner's name is placed on the
department's records, that's a transfer.
http://www.dmv.ca.gov/pubs/brochures/howto/htvr1.htm

>> How to register the car in CA in your name (click on links for full details)

If a resident of California acquires a vehicle from another state or
country, fees become due the date the vehicle enters California and
must be paid within 20 days to avoid late penalties.
You will need to:
    * Complete an Application for Title or Registration (REG 343)
    * Submit the out-of-state title signed by the seller
    * Provide an odometer mileage certification signed by both you
(the buyer) and the seller
    * Provide evidence of the California Smog Certification
    * Bring your vehicle to a DMV office for verification of the
vehicle's identification number (for your convenience, we recommend
that you schedule an appointment)
    * Pay the fees
http://www.dmv.ca.gov/vr/osreg.htm#BM2561

DMV California
How To Register A Nonresident Vehicle
Change of ownership:
If there is a change of ownership, the title must be signed by the seller
Registering your vehicle:
The following is required to register a nonresident vehicle...
http://www.dmv.ca.gov/pubs/brochures/howto/nonresident.htm

>> How to sell it once it's a CA vehicle (click on links for full details)

How to Change Vehicle Ownership
How To Get Started
You will always need:
    * California Certificate of Title or Application for Duplicate Title (REG 227)
    * Signature(s) of seller(s) and lienholder, if any
    * Signature(s) of buyer(s)
    * Transfer fee
You may also need:
    * Smog certification
    * Use tax and/or various other fees
    * Additional documentation
http://www.dmv.ca.gov/pubs/brochures/fast_facts/ffvr32.htm

Buying or Selling a Vehicle (Changing Vehicle Ownership)
http://www.dmv.ca.gov/vr/sell.htm

I was glad to work on this for you. If you have any questions, please
post a clarification request and wait for me to respond before
closing/rating my answer.

Thank you,
hummer

Google Search Terms Used: california dmv transfer ownership out of state