but you would have 10 years before anything would cause a problem?
If you have a 10 year permit that has not been canceled then they still show your name etc. as having a permit for the 10 years. If you sell the RV or leave it in Mexico you cannot cross into Mexico with another RV until the original is canceled. If you want to bring in another RV you need to use another name or some other way of confusing the system - but don't get caught. If you have no intention of ever taking another vehicle into Mexico then there isn't much they can do - maybe.