A car can be sold at any public auction where the seller resides, including California. The regulations in each auction will differentiate depending on which company hosts it, but most require an auction fee.
When registering a vehicle for an auction, a seller must apply for a position in the auction. The car may or may not gain access, and if it does the seller will need to pay for its position. Often, after the car sells, there will be another fee. The last fee is commonly referred to as the final value fee, which is a commission based on the percentage of the total that the car sold for.