I went through this with the sales-rep specifically, the Trans cooler was standard on the '09 (at least for the v6). The $500 option is for the wiring and hitch.
The reason for my wanting the Class III for my trailer is a pain in my A$$. My pop-up camper is just less then 2,400lbs, it has the a storage compartment at the front. The camper maxes out tongue weight (15% of GVW) pushing it a couple of pounds over the 3500lbs. The trailer sticker says it needs a class III hitch.
The oem class II hitch can only take 350lbs tongue weight. You can tow 3500lbs with the minium 350lbs tongue weight. I'd hate to have my load shift or the weight move (like going uphill), its nasty when the tail wags the dog.
The accessories for the 2" receiver are nicer as well.
In my next life I'll go retro with a nice light Boler.
