Cerakote Trim Coat Kit for all exterior black plastic trims. Used it on my outdoor dwelling '13 BMW X5 with black sport package fender flares. 3 years of SoCal sun, still looking a deep rich black.

Door edge protector (too many options to link), to cover up the sharp edge at the end of the rocker trim, so you or your passengers don't scrape your flesh against it. I think* this is the rocker trim just aft of the rear doors.

If you won't be ceramic coating your truck, Aerolon is an excellent alternative and far superior to any kind of automotive wax—synthetic or otherwise.

Off road prep... Tire air deflators (preset or adjustable to a certain pressure) are handy for airing down. They save you from guess-work and tedium of trial-and-error. And, if you're not buying Rivian's, a vehicle recovery kit with soft shackles.

To avoid the power tonneau from binding and failing, a soft bristle brush (so you don't scratch paint) or duster to sweep the powered tonneau cover and tracks. A powerful car vac would be an excellent addition for failure prevention.

Then, whatever phone mount you desire, if you are one of those who just can't live without having your phones at the ready.

Everything else I've seen so far, like the various vinyl decals, feels like #crapgadget. This is sure to piss off those who never outgrew stickers and tacky trinkets.