What tactics did you use when buying your truck from dealer? Certified pre owned vehicle

I’m looking at a 23’ 1500 Laramie 5.7 L Hemi w/ e torque for $40k (25k miles). Looking on the market that seems relatively fair pricing wise. After more research I’m concerned regarding longevity. I am good about general maintenances like oil changes, etc.

While I’m negotiating on the truck, is there anything you all had the dealer do prior to purchase to your truck? It needs a bed liner which they said they would throw in for no charge.

It’s been about 10 years since I went car/truck shopping.

Any advice appreciated!