Perhaps because he was a CHIEF CONSTABLE? Do you expect the chairman of your company [if you are employed in such a manner] to come to work in a Mini? No, of course not. Are you also going to complain about the wages he is paid, because he could easily 'get by' on a £35k per annum salary? After all, that's paid by the taxpayer as well! He's worked hard at his job and is suitably rewarded. Public services get supplied company cars at knock down rates anyway, and besides, with a valuable company car, he will be paying MORE tax back into the system, than if he had a Fiesta.
Honestly, it's like your not allowed to be successful anymore, because everyone will bemoan of the things success brings. Maybe we should all aspire to work in Tesco stacking shelves...