Don't know if it's a new promo, but my Kubota dealer came back from some sort of regional meeting with a bunch of very nice caps with KUBOTA inscribed across the front - giving them out for free.
As to cup holders, the post by Sullivan is right on. I already have one. I just cut off the hook part of a $1.50 Auto store cup holder, drilled to holes in the shaft about 3 inches apart and a similar 2 holes in the thick plastic casing on the side under my instrument panel (L3410), and fastened it in with 2 stainless steel bolts/nuts/washers (had to temporarily remove 1 of the bolts holding the plastic sheathing so I could get access high enough on the panel to be within an easy reach for a beveridge, just under and to the side of the steering wheel). Holds soft drinks (and beer) just fine. Cheap and very stable - my tree care guy came by and remarked that his Kubota hadn't come with the drink holder option - I just laughed and told him that if Kubota had a drink holder option, it'd likely cost more than the few bucks that my real basic gizmo did - so he built himself one.