1) Hit up a site like CarGurus (they expanded to Canada in 2015:
https://ca.cargurus.com/ ), and pretend on the site that you want to buy the same make/model/featured truck you have now, with the same mileage, etc... this will show you what the dealerships are *selling* your truck for right now. Expect to get (if lucky) 20% less than that average figure, and only if you print out and show said dealership those figures.
2) Take your truck to 3-4 different dealerships and make them all bid for it, using the CarGurus (or similar) prices as a guide. Play one against the others (
"well, Dealer X had the best offer, and they said they were willing to give me $zzz for it. If you were to increase that offer by $500 or so, I think it'd be worth the drive out to you..." ) Sweeten the deal by promising that if they increased the offer by $500 on top of all that, you'll happily shop their place first (make no agreement to buy from them, but to "shop" form them first, and only
after you've got their best offer in writing!) Oh, and don't be afraid to shop it out to non-FCA dealerships if they're part of a larger conglomerate (for instance check out the idea of selling it to
ButtHead Chevrolet if you know that a
ButtHead FCA dealership exists in the next town or something... you might be able to sneak it in for a bigger price if they're willing to take your truck in, thinking they can transfer it over.)
3) Don't get your hopes too high; brand-new vehicles lose a megaton of resale value the moment the ink dries on the contract and they hand you the keys. This is partially why I try to always buy used... my current (bought-used last year) truck still has slightly more KBB value on it than I paid for the thing.