Understand your frustration, but that could have been (and should have been) caught years in advance by any competent mechanic or DIYer working on the vehicle. I sold my 2010 Murano after 8 years and it had only superficial surface rust. I live in New England with heavily salted roads and lots of rust potential. In the winter I take the vehicle to car washes with undercarriage washing and the rest of the year I wash it myself to ensure all that corrosive salt is removed from under the vehicle. It happens to ALL vehicles if they are not properly maintained and cleaned.