Motoring: Why it pays to watch the clock

EXACTLY HOW far do you have to go before you find a used car with an altered mileage? As I've just discovered, not very far at all. Just a few miles down the road in fact, provided my own is telling the whole truth.

"Clocking" is estimated to cost used-car buyers well in excess of pounds 100m a year. According to the Institute of Trading Standards Administration, a car's value increases by an average of pounds 30 for every 1,000 miles removed from the mileometer reading - which makes clocking one of the easiest ways to increase profit when selling a car.

Strangely, the act of altering a mileometer is not illegal in itself. However, a vehicle being sold or offered for sale with its mileage altered is illegal. The problem is proving who actually did the clocking and prosecuting them. If I have learnt anything over the last week it is that buying a used car is still as dangerous as ever and that there is no such thing as a cheap Mercedes.

My most recent brush with a clocked car began when I was idly flicking through my local Auto Trader and saw in the colour section a cheap Mercedes. The advert read: "Mercedes Benz 190E 1989 (F reg) blue, 99,000 miles, immaculate condition, fully loaded, Tax, MOT, pounds 3,750". A Mercedes like this would usually be pounds 5,000 plus.

I arranged to meet the seller, whom I shall call Herbert, after he got back from work. Yet there he was polishing up a 10-year-old Jaguar saloon. A BMW further up the drive was also his. This was supposed to be a private sale. "So are you a trader?" was my first question.

A cursory look at the Mercedes also set alarm bells ringing. A tow bar. Never a good sign, because towing puts strain on everything. Contrary to the ad, the road tax had expired. There was some poor quality repair to a rear-wing scrape and the bumper was also not quite square, suggesting a minor knock. Inside, the door trims were shabby, the material peeling back from the window frame.

In the fading light I felt the tyre tread; at least two tyres were illegal. As for the paperwork, there was one MOT dated six months previously and the registration document. Apparently everything else had been lost in a house move.

The golden rules of Mercedes buying are a full service history, tidy condition and an automatic gearbox.

I wondered if I could break all the rules and still end up with a decent Mercedes for next to nothing? First I wanted to make some enquiries.

I phoned HPI. For pounds 31 they confirmed that the registration and chassis number did indeed relate to a 1989 blue Mercedes 190E which had never been written off, wasn't stolen and had no finance charges outstanding on it.

Good news. Next I rang the Mercedes main dealer whose logo was on the registration plate. Although they were not the original sellers they had serviced the car. The last time it was in their workshops the mileometer reading was 211,767. Rather more than the 99,000 displayed. Bad news. The MOT certificate had read 93,000, so the clocking dated back at least 6 months. Herbert took the news well, but whether he was the actual clocker I'll never actually know.

Auto Trader was interested to hear of my discovery, but apart from refusing any more advertising from that source could not take any further action. Trading standards officials apologised, but unless Herbert could be proved to be running a business there was nothing they could do.

The police could take action but needed proof that the seller knew the mileage was incorrect and was intentionally misleading the buyer.

Buying a used car can be a nightmare, but only if you let it. Be methodical, be fussy, don't trust anyone, make enquires and, most important, don't buy a blue Mercedes registration number F321 ACL, chassis number WDB2010242F581421.

Call HPI on 01722 422422