DMV doesn't care who pays it. They won't process the title transfer of the car as long as there're unpaid taxes or fines. Imagine I've already paid the money to make the purchase, and later going to DMV to transfer the car title but find out I couldn't due to unpaid fines. What could I do? Either paid the outstanding fines or sued the owner to revert the sale. Headaches all around. I didn't go through with the purchase at the end.

I talked to another car dealer and asked him about it. He said this kind of car was usually sold to people in another states, where their DMV won't enforce California's taxes and fines.

The lesson here is be sure to check for a clear title on the car, including DMV fees and fines, before making a purchase.