Yes, but in order to REGISTER you needed to provide name, address, a signature AND a "California driver license or identification number, if you have one, or the last four digits of your social security number, if you have one. If you do not have any of these numbers, the state will assign you a unique identification number."
In CA, voter registration is handled at the county level, and the registrar is responsible for validating applications. Which may be the reason we have less trouble than other states. Now if we had a citizenship requirement...
Sorry. Motor-voter went into effect in 1997. All the people have to do is check a box on their DMV application. ‘I am a citizen and entitled to vote’. No proof of citizenship. That's California started going seriously down hill.