You got me curious. Here is what I found about smog requirements in CA.
Cars Six Years Old and Newer
Most newer cars will be exempt from smog testing for a certain amount of years. You will be charged an annual smog abatement fee when you register your vehicle, rather than being required to provide smog certification.
Title Transfer and Smog Requirements
When you sell a gas engine vehicle that is 4 years old or fewer model years old, a smog certificate will not be required in order to transfer the title. The buyer will pay a smog transfer fee of $8. If the vehicle sold is more than 4 years old model years old, the seller must provide evidence of a current smog certification except in any of the following situations:
The vehicle transfer occurs between a spouse, sibling, child, parent, grandparent, or grandchild.
The vehicle was registered and biennial smog certification was submitted to the DMV within 90 days before the date the title transfer took place. A vehicle inspection report may be required for proof of certification.
Vehicles Inspected in Other States
Because California has such stringent rules regarding smog emissions, vehicles that passed smog inspections in other states might not meet California's standards. Therefore, if you buy a vehicle from out of state, you should double-check with the DMV to find out whether you need to get your vehicle inspected in California before you will be allowed to register it.
If your registration expires while you are out of state and you require an update of your smog inspection sticker, you must submit your registration fees immediately to avoid late fees. Upon your return to California, you must get your car's emissions checked and submit the proper paperwork to the DMV. You will not receive your new registration or new sticker until the DMV receives the updated inspection report.
