The most successful Audi ever will be replaced in the UK next March when the all new A4 saloon reaches Britain’s showrooms. The model that attracted 1.5 million buyers across Europe has now been completely revised from the ground upwards with a larger, roomier bodyshell, fully independent suspension all round and two all-new lightweight aluminium engines - a 3.0-litre V6 and a 2.0-litre four.