The same is true of the BMW 7-series. Now, I like this car because of its hairy-chested macho appearance and excellent road manners, but after a week in it, I felt like I had just watched a film in French. I had the basic gist of what was going on, but had missed out on the finer points.

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There is no doubt the 7-series is too complicated: almost every function of operating the car requires re-learning, from selecting forward and reverse gears on the little stalk on the right of the steering wheel, switching the parking brake on and off using a button by the door, to trying to adjust the air conditioning using iDrive.

But I don't find iDrive as obstructive as some have. The big silver dial seems to work efficiently and accurately enough. It's just that once you get into the menus you are confronted by a forest of options, modes and abbreviations which requires poring over the manual for clarification.

BMW's meticulous quest to be the automotive Einstein even stretches into wiper blade design. If you leave your 730i sitting around for too long, the windscreen wiper will move every couple of days, shifting the wiper edges from one side to another, which apparently prolongs the life of the blade.

If you drive a £50,000-odd car, I can't believe prolonging the life of wipers by a few months will be a high priority, but it's here and it's cunning and it shows how far BMW is prepared to go with its technological tour de force.

The 231bhp 3.0-litre petrol unit, despite being a cracking engine in many other BMWs, is the weakest in the 7-series range and there are times where it feels it, especially when you are overtaking.

The extra mid-range grunt of the 3.0-litre diesel, which has a third more torque than the 730i, would help, but for doing the job of swooping along motorways the 730i is a pretty unruffled and smooth performer.

It has a decent combined fuel economy figure of 26.7mpg, which means 500 miles on one tank, with a carbon dioxide figure of 257g/km placing it in the maximum 35% benefit-in-kind tax band. But with better fuel economy, better residuals (CAP reckons the 730i will retain 37% of its cost new after three years/60,000 miles compared with 39% for the 730d) and a price tag about £2,500 cheaper, the diesel Seven is the one to go for.

A winning combination of receptive steering and sorted suspension make this the driver's favourite in this sector and there is no doubt this is a very clever car, but sometimes it drowns you with its intelligence rather than helping you to float along. With more time in the 730i, perhaps I would have been able to learn its language.

Model: BMW 730i
Engine (cc): 2,979
Max power (bhp/rpm): 231/5,900
Max torque (lb-ft/rpm): 221/3,500
Max speed (mph): 147
0-62mph (sec): 8.1
Comb fuel consumption (mpg): 26.7
CO2 emissions (g/km): 257
Transmission: 6-sp auto
Fuel tank capacity (l): 88
Service interval (miles): variable
Price (OTR): £47,025