We use these for my kids and they work really well. No leaking and keeps water cold all day if you add some ice. Much cheaper than some of the name brands
https://www.takealot.com/double-wall-stainless-steel-insulated-water-bottle-straw-chug-li/PLID93641498
I know this is an old thread - but I'm wanting to buy the same car and also wondering about claiming the VAT - what did you end up finding out or doing?