Question about additional add-ons

Got this truck a year ago and I'm still finding out features about it, and I'm sure there are many more. However, would there be anywhere the additional add ons were cited like in the owners manual or something? I've looked through there but really didn't find much, maybe I'm looking in the wrong place?
It's the SR5 trim if that helps.

 

Not so much add-ons but reference info (attached).

As for add-ons from the factory, there was a factory skid plate (part# PT212−35040) although that is a unicorn today. There was also a toyota offered alarm, the RS3200. I've included the manual and programming instructions below. Toyota also offered a branded bed mat, drop in bedliner (both over the rail and under). Some Tacomas came with a toyota roof rack (another unicorn in terms of locating the parts).

About all that comes to mind. Cheers.

 

Huh, didn't know the bed liner wasn't stock, also I got the factory skid plate. No rs3200 tho, never checked behind the kick panel, they're usually pre wired for them tho so it's basically just buying a module and plugging it in.