I bought 2 metal cans from my local Lexus dealership in late August for around $70 bucks each. I've read on here(all anecdotal) people having mixed luck ordering OEM fluid from online sources, at a cheaper price. Some ship, others say it's hazardous and won't.
I came away with the same determination but they appear to work with some modification. Pretty sure mods we're described in that thread, I did not go back and read the whole thing recently so do not know for sure.
Tundra wheels on 100 series photo thread
This thread has examples of those rims as well as other Tundra rims. TRD/pro; the all black rims and the black with machined face are the same except for final finishing.
Search on car-part.com. year, make, model, computer(engine), I saw results ranging from $100-150. Also enter those part numbers on eBay, I saw some result there too.
Do keys need reprogrammed after an ECU swap?
ENGINE COMPUTER ECU ECM FOR LAND CRUISER 1737020 03 MAIN ECU RAN NICE W-KEY | eBay...
Monstaliner Bedliner
Lots of examples in there with a similar product. (DIY, roll or spray, with good surface prep) Been awhile since I went through the whole thread, there may be a few 100s as examples in there.
Mine is not connected to anything either. Seems to be a vent/breather. And that is part of the charcoal canister. Should see it labeled on the vacuum hose wiring diagram if you still have it applied on the underside of the hood.