Hi Jim,

I'm afraid there's no black and white answer to that question, as it's not a measurable thing you're asking us to rate those cars on. And it varies from engine to engine. The new 2.0-litre diesel engine in the BMW is exceptional, helping with quietness, while BMW's petrol engines in the 3 Series are generally smoother and quieter than the Mercedes equivalent. The Audi's aren't far off, and a significantly revised A4 is due in the country later this year anyway.

In terms of interior finishing, they're all of very high quality. I personally love the Mercedes steering wheel and the tactility of its buttons and the layout of the dashboard, but much rather the centre console and some aspects of the BMW's infotainment. I don't massively like the layout of recent Audi cabins, but there's no arguing with their quality.

Really, there's no substitute for going and sitting in these cars for yourself so you can form your own opinion.