Square cup hole solution
I happened upon this discovery when my truck still had the dealer plates. On my 2000 taco 4x v6, it has square center cup holders. I dont know of any square cups except Double Big Gulps but i hate soda.
Tundras back in 2000 also had these removable round cup holders. It so happens that the 2 cup kit fits perfectly in my square holes. One is completely round and the other has a handle cut out for coffee i guess but it has to have a lid to ride in my truck. With the round one, and a canned beverage with a koozie will keep the drink very stable and very suitable for bouncing around. Best mod by far.