It is difficult to understand why you ask the question you ask, but frame it by the headline you wrote. Your question has absolutely nothing -- NOTHING -- to do with alleged judicial corruption.
to answer the headline questions: When you don't agree with the judge's decision, you appeal. There is no one to complain to, no one to report it to, unless there is some evidence of improper conduct by the judge. Improper conduct is NOT established by deciding the case against you, no matter how certain you are as to the wisdom of your position. Here is a good statement of the limits on complaints against judges:
"An error in a judge's decision or ruling, by itself, is not misconduct. Appeal may be the only remedy for such an error, or there may be no remedy. The Commission is not an appellate court. The Commission's authority is limited by law to investigating the complaint and, if appropriate, imposing discipline. The Commission does not have the authority to change a judge's decision or ruling or to issue orders in any case, including ordering anyone to be released from jail, granting a new trial, disqualifying a judge from hearing a case, assigning a new judge to a case, or granting or changing custody, visitation or child support orders. Neither the Commission nor its staff is authorized to give legal advice or respond to requests for assistance with individual legal matters."
If there is actual evidence of improper conduct, you can make a complaint to the CA Commission of Judicial Performance. Here is the link to the complaint process: http://cjp.ca.gov/file_a_complaint.htm
If you think you got scammed by a car dealer, you may want to make a complaint against the dealer's license to sell cars to the CA Dept of Motor Vehicles. DMV can investigate and issue very significant and onerous penalties and remedies, including shutting down the business, if there is evidence to support a complaint of fraudulent or improper conduct. Here is the link to complain there: http://www.dmv.ca.gov/consumer/invest/inv172.htm
Frankly, it sounds to me like you got a very sound and practical remedy from small claims court (no good deed goes unpunished) that you did not follow-up on through enforcement. You may want to contact the clerk of the court to determine whether your case is still pending for compliance with the court's original ruling.
My responses to questions on Avvo are never intended as legal advice and must not be relied upon as legal advice. I give legal advice only in the course of an attorney-client relationship. Exchange of information through Avvo's Questions forum does not establish an attorney-client relationship with me. That relationship is established only by individual consultation and execution of a written agreement for legal services.
You file an appeal. Nothing in your facts points to judicial corruption.
The above is general legal and business analysis. It is not "legal advise" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.