The main reason the fee is so high is that it considers many factors like smog inspections, weight certificates, license plates, etc. Since it charges an additional fee for all of these, the overall amount is quite high. And another of the many reasons for registering a car in California costs so much is because people have to procure license plates before they have their cars registered. It is legally required that you obtain the latest license plates for your car before you present it to the responsible body for registration.