Hi Sandy,

That budget probably puts you into a 2009-2010 model 3 Series, so the challenge is not so much to choose between those three models, as tracking down a petrol-engined version in the first place. To be honest, the best is probably the 318i. It basically has the same engine as the 320i (a four-cylinder model by then, loses out by 27hp, but has CO2 emissions that can be as much as 40g/km lower (depending on the wheels and tyres fitted), so it will be kinder to you in both tax and insurance.