Audi A4 - Pictures

The A4’s lines aren’t as fresh as the Merc’s, but its simple, solid and unfussy styling is a key attribute for many customers. S line models get aluminium trim around the window line and more prominent side skirts.

Cabin quality in the A4 can’t be faulted. Not even the BMW has such tactile plastics or better trim. The standard multifunction wheel has roller switches that operate the audio and trip computer information.

The Audi has an identical boot volume to the 3-Series and lags 15 litres behind the Merc. There’s a space-saver spare, while folding rear seats cost £250. An £85 storage pack adds front under-seat trays and rear cup-h

One of the most widely used diesels around, the 2.0-litre TDI is found in a host of VW Group cars. Here it outperforms the BMW’s unit and runs the Mercedes close for in-gear response, but doesn’t have the smoothest delivery

While the handling is secure, the Audi can’t match the delicate balance of the rear-driven BMW or Mercedes. The steering also suffers from kickback under load. Keen drivers will certainly have more fun in the 3-Series.