Does anyone know if Mercury offered a tow prep package as an option for the 2010 Mercury Mariner Premier w/4W Drive and the 3.0 V6. It is my understanding that a tow prep package included a tranny cooler, a beefier suspension and factory installed wiring harness. Otherwise, are you able to simply add a hitch and wiring harness and call it a day? And you would still be able to trailer up to 3500 pounds? Or do you need a tow prep package for this? If not, why do some car dealers mention a tow prep package and others don't for the same year and make of Mariner? Hope there are some good Merc gurus left out there to answer this question. Thanks a lot.