I agree, not hiding any problems with the car. However, it is good to be up front when dealing with a private buyer so they don't get "surprised" later. Anywyas, a brand new engine that was replaced by factory warranty is a good thing in my opinion. I think it's understood that with thousands of cars coming out a few will be undoubtedly bad and need stuff repaired under warranty. after all, that's what warranty work tries to take care of.