ParaP is correct. If you drive the car in CA, sales tax is due.
Another alternative to avoid the tax is to have the Dealer employee themselves drive the car across state lines and have your signature notarized on a particular CA DMV form that states you, as the buyer, have taken delivery out of State.
The option that ParaP mentioned is to have the car trucked across state lines and the trucker's "bill of lading" serves as proof that the car was delivered out of state.
If you do drive the car in CA, the dealer will collect the sales tax and sell you a "one way trip permit" (about $15) that is good for seven days allowing you to move the car from point A to point B (usually your out of state address).
Finally, many States are "reciprocal". This means that if you pay tax in CA, you do not have to pay the sales tax in your residence State. However, if your State's tax rate is higher, you will have to pay them the difference. If your State's tax rate is lower, you will NOT be refunded the difference in tax rates.
If the tax rate in the area of CA where you purchased your vehicle is "close" to what you pay in your State of residence, this is an acceptable alternative.
You will need to check with your State's Department of Motor vehicles to see if your State has a reciprocal agreement with CA.
http://www.boe.ca.gov/pdf/boe448.pdfLastly, if you took delivery out of the State of CA and avoided the payment of sales tax, the car CANNOT return to CA (was 1 year, now 90 days) or CA will presume the car was intended for use in CA and sales tax is due. That prevents CA residents from doing an out of state delivery to avoid paying the sales tax.
If you drive a "fancy, pricy car" in the Sate of CA with out of Sate license plates, you WILL be a particular target of the CHP. They look at you as taking money out of their pocket. You better possess an out of State Driver's license and out of State insurance card.