How do costs work out for fleet buyers? Well, leasing costs are identical, at £391 a month, and it’s a similar story in terms of company car tax, with the Audi having a scant £275 advantage after three years. Private buyers will get larger discounts on the BMW of buying outright, but the Audi’s PCP is £14 a month cheaper. Only the A4’s standard-fit rear climate control, xenon headlights and emergency city braking versus the 3 Series’ full leather seats separate the broadly similar kit levels.