The cartridge-style oil filter on a new 3.6L engine is not where you expect it to be. It is actually located in the front of the engine bay next to the engine cover. It can be identified by its black hex nut. See photo.
Yes, I was surprised. I have a 2010 3.5 and people have been complaining about how tight the factory install was. When I took delivery on my 2011 Durango, the salesman showed me where the oil filter was, ON TOP! Now, does this mean we can change our own filter with little effort? Well, maybe not as one needs to drain the oil and grease the car, so might as well take it in and have them do it. I don't do oil changes.