I think this comes close to the best answer. If the OP wants a new car but can't afford it personal they get it via the company. If they want be most efficient method then buy it personally.
This comment at the end of their post is exactly what I mean...
OP just needs to work out what the real aim of this exercise and then pick on of the two options above. I'm not sure picking at all the numbers when in reality they don't have the cash reserves is really achieving anything, particularly when numbers threads often go so badly wrong on here.Again... yes if you have the cash price for a car sitting in your personal account, this would be the best way, but if you don't, then buying a company car may not be a bad option compared to taking the full car price as divs.
To be fair as well looking at the OP's last post they've made the decision already and it's pointless trying to convince them otherwise.