Financial Ombudsman Service (FOS): If the lender doesn't resolve your complaint satisfactorily, you can refer it to the FOS for an independent review. However, you typically have six months from the lender's final response to do so: https://www.financial-ombudsman.org.uk/
Time Limits:
Generally Six Years: There's generally a six-year time limit from when you discovered the mis-selling, or could reasonably have discovered it, to make a claim.
Seeking Legal Advice:
Complex Situations: For complex cases or significant financial losses, consider seeking legal advice from a solicitor specialising in mis-selling claims.
Remember:
Be wary of car finance adverts that seem too good to be true. If the reality significantly differed from what was advertised, and it influenced your decision, you might have been mis-sold. By gathering evidence and complaining to the lender and potentially the FCA or FOS, you might be able to seek compensation. Act promptly and remember the time limits for claiming mis-selling.