How does California dmv calculate the purchae price for use tax for buying a used car from a private party?

Dmv in Ca determines the use tax by whats on the transferring documents. In your case 8.25% of your purchase price. Don't be unreasonable or they will flag it and send it to the tax board. Don't try saying you spent 2,000 on a 40,000 car. You don't want to be flagged. So be reasonable. Just keep in mind is the $ worth your soul, (most would say @@@@ yeah, lol). You can't scratch out on the title or alter #'s, they weren't born yesterday. If you lower your price nothing may happen or you might get a bill from franchise tax board saying you owe more money. Say you do catch a break and get a 40,000 car for 2,000. Declare that the purchase price was less for whatever reason on a statement of fact form. The best kind of flag is the one with paperwork to back it up, that way they can push it right by and not bug you. Enjoy the new car!!!

Looking at the form from the California DMV it looks just like Wisconsin's where you put in whatever price you bought it at. You do have to sign an agreement stating the the information is correct on the page, so I wouldn't lie about the price or anything. So, don't worry about the Blue book value or any of that stuff. Just fill out the price and pay the tax on that. Good luck with your car!

They take the amount on your bill of sale and use that.