My BMW and I have been inseparable colleagues over the last month.

For one reason or another, I’ve ended up doing a tour of Britain, racking up 3,000 miles in three weeks. What did this teach me about the 120d?

Firstly, there are very few places to pack away the used sandwich wrappers and empty crisp packets. The infernal plastic bottles rolling about in the footwell drive me mad.

But dig underneath the detritus of an adopted life as a travelling salesman and the 120d performed admirably.

In fact, it was as fun to drive after the 2,999th mile as it was when I set off on the first one.

It’s a lovely car to drive, and that’s so important when you are doing a lot of it.

On a wide flowing stretch of the M6 in Cumbria you could wind it up and sweep, fast and stable, through the long bends in the honey sunset.

Yet on a grubby morning in the Warrington rush hour, you can just let its prodigious torque inch you along with barely any driver input.

The sports seats are fairly tight, especially for my pork pie-bolstered frame, but they don’t pinch and don’t give you backache.

Through all of this, the 120d averaged nearly 50mpg. In fact, when I was on schedule and able to really cruise the trip meter showed that I was getting well over that, and a £45 tank of fuel would last me nearly 600 miles.

So what are the downsides?

Well, you come to realise just what a small car it is. It’s fine if you are in the front seats, but once there are a few bags in the boot it is pretty much full and there isn’t much room in the back for rear passengers either.

The other major criticism is easily remedied if you throw some money at it.

For five or six years now, as a spoilt road tester at Fleet News, I can only remember driving one long-termer that didn’t have satellite navigation, and that was a Jaguar XJ6.

Until the 120d, that is.

In the course of my travels I had to visit places I didn’t even know previously existed, all without the aid of electronic maps. My word, did I learn how the other half live.

Poring feverishly over bits of paper printed off the internet, constantly trying to confirm I was still on the right road.

I reckon the added stress and extra work involved in getting to somewhere unknown doubles the effort of the journey, because if you go wrong, you’re knackered.

Your bits of paper don’t just re-route you. Oh, for an admonishing digital woman with a Home Counties accent instructing me to turn round.

Built in sat-nav for the 120d is a hefty £1,570. I’d gladly pay it if this was my daily working life, though.

Fact file

Price: £21,995 (£23,585 as tested)
Mileage: 6,100
CO2 emissions (g/km): 129
Company car tax bill (2007) 40% tax-payer: £130 per month Insurance group: 14 Combined mpg: 57.6 Test mpg: 48.9 CAP Monitor RV: £7,675/39% Contract hire rate: £418 Expenditure to date: Nil Figures based on three years/60,000 miles