Just how difficult should it be to arrange a test drive before buying a new car? Not as difficult as it is if you happen to be dealing with Hexagon BMW in north-west London, I can tell you.

The Rendell household will change its car next spring, so enthusiastically I filled out the contact form on BMW’s web site to arrange a road test of the new 177bhp, sub-140g/km 520d SE Touring.

A bod from Hexagon rings back keen-as-mustard. But as soon as he discovers the car will be supplied by a lease company, talk of a test drive is off the agenda. Staggering considering that fifty per cent of new cars sold in the UK go to fleets, and I’m guessing that the percentage is much higher in the premium segment.

In some ways I can’t blame the young salesman. He’ll set aside an hour of his time and any sale, along with a commission, is likely to slip through his hands, unless I can persuade the lease company to put the deal through his books.

But dealers are there for other reasons than to fill salesmen’s pockets with commission. What is the point of BMW or any other car-maker having a high profile, nationwide network of dealers if they can’t offer the most basic of services to customers? Surely a test drive is one of those basic services?

BMW’s response to all this is illuminating, too. To keep dealers on their toes, they follow up web requests at the customer service department. When I relate my experience, I’m told to expect a ring back from Hexagon. But there’s only silence. And no further interest from Customer Service.

This is not the first time I’ve been snubbed by a dealer when the dreaded words ‘company car’ are mentioned. A couple of years ago I approached HR Owen for a V70 test drive to replace an Audi A4 lease car and got the same bum’s rush from a bored salesman.

To its credit, HR Owen’s fleet sales team redeemed the situation, although only after I got persistent. And in fact that overnight test drive secured the sale.

Later when I related my experience to cheeses at the Volvo importer they rolled-their-eyes skywards and shook their heads.

The arrival of the new V70 has already sharpened Volvo’s game and now we’re on HR Owen’s database, it’s all we can do to bat-off enthusiastic salesmen.

Car industry experts will tell you that it’s much more difficult and expensive to win new customers than retain existing ones. Now I can see why.

I’d like somebody to tell me what is the justification for assembling a nationwide dealer network, asking entrepreneurs to invest millions of pounds in high-cost facilities, if they then ignore fifty per cent of the UK new car market? Puzzling indeed.