The simple explanation of estoppel is as follows: estoppel is basically where a person makes a promise or gives a representation which causes another person to adopt an assumption (ie believe something) that some legal rights are going to be recognised or awarded. That person enacts (ie goes forward on the basis of..) in reliance on the representation or the promise, and in the circumstances the Court can take the view that it's wrong or unconscionable of the person who made the promise, to go back on it.(posted 8547 days ago)So in the case you mentioned, the guy thought it was clear that he was entitled to the money because the error was not rectified for 18 mths. It's a very grey area of Law and unless you have a good legal brief I would be cautious about attempting to apply it to repo cases, if any contact has ever been made by either the Lender or the MIG Co under Rights of Sub. If I sound like a lawyer it's because I tried this route..and failed.