A seller may not sell a car in CA without having the car pass smog UNLESS it is sold as "non op." If this is not the case the deal must get unwound and if seller refuses to do so you can sue seller effectively.
Contrary to popular belief, a Judge in Small Claims can return the parties to their original condition, i.e. you get the $600, he gets the car. Clearly there was fraud or fraudulent intent. A=Oh, yeah, also as mentioned here, it is illegal to selll a car that has not been smogged PRIOR to sale.
An unwinding of the sale is doable and can be done in Small Claims. I would sue in Small Claims for the value of the contract and request that the judge either award $3000 OR order the parties returned to their original condition and that it be done by a date certain.
If you have further questions, be sure to speak with a lawyer that knows about Small Claims.
-Adam Jaffe Law Office of Adam Jay Jaffe PO Box 2437 Camarillo, CA 93011-2437 (805) 504-2223 www.smallclaimsappeals.com Adam@SmallClaimsAppeals.com This posting is provided for “information purposes” only and should not be relied upon as "legal advice". Nothing transmitted from this posting constitutes the establishment of an attorney-client relationship. Applicability of the legal principles discussed here may differ substantially in individual situations or in different states.