BMW 5-Series

It's no good. Ably assisted by my two-year-old son Luke, I've flicked through countless back issues of Auto Express and I still can't find a car I would rather run than the latest addition to our fleet: a new BMW 535d Touring. Recently facelifted, the BMW now has an adapted iDrive cabin control system as well as an intelligent alternator which doesn't draw power from the engine constantly.

The latter alone is meant to have improved fuel economy by 3mpg, even though the new 3.0-litre twin-turbo diesel puts out more power than ever - 282bhp to be precise. So far, we have no reason to doubt BMW's figures. I've now covered more than 5,000 miles in the 5-Series Touring and averaged 35.6mpg, with a best of 38.8mpg on one tankful which lasted over 580 miles. But what I really enjoy about the 535d is its ability to play at being a sports car when the mood takes you. And since for 70 per cent of my journeys I'm the only one in the cabin, I'm thoroughly enjoying the BMW's taut dynamics.

It's a bit too focused at times, though. While I think the M Sport bodykit looks great, the big alloy wheels, sports suspension and low-profile run-flat tyres deliver a ride quality that's most generously described as 'positive'.

The boot may not be as big as a Mercedes E-Class Estate's, but it's packed full of useful features. Separate opening tailgate glass, a load cover that retracts automatically, and with no spare, a spacious two-level underfloor cubby. No family task has proved too much for it yet.

The 535d hasn't been entirely fault free, however. A couple of weeks after it arrived, I noticed a blemish on the driver's side door mirror. The glass defect rapidly grew, so I rang my nearest dealer, Dick Lovett BMW in Hungerford, Berks, which agreed to see the car at very short notice. However, once in the garage, I had to wait 50 minutes before one of the service team came to assess whether it was a warranty repair or not - a task that took less than a minute.

Luckily, they think it's caused by moisture getting between the layers of glass during the construction process. Hopefully, the dealership will prove more efficient when it comes to doing the warranty work. In the meantime, my search goes on.