Actually... I would take this one to court. The cop should have called another one to get involved. There are certain laws to protect you from this. You can say you were intimidated coerced confession etc (due to it being his wife/his car) - if you were to take it to court you may be able to get anything you may or may not have said at the time thrown out. Get an attorney if so inclined.
PS. Shouldn't have admitted to backing up
