You will need to present to the county DMV: your bill of sale, application for title, the sales tax receipt along with the signed title.
Colorado residents in an emissions-regulated county will need to make an appointment with the special inspector to get a form DR2365 which allows for the vehicle to be tested. With a non-conforming vin, the VIN explosion software used does not work.
Out-of-state customers: please research your local laws and regulations. We do not offer California Carb Compliance, however, we can help with references for those who can help.