"minimum value" on a car sale in california?

[jfresh]

i'm buying a car from a private party, and we are going to put a low sale price on the transfer of title, which is how the DMV determines the tax. i've heard that some states will ignore that price and take the Kelley blue book price and tax that instead. anyone know if they do that in CA, or if they get suspicious or ask questions if the price is too low?