Simply possessing enough cheek to think the unthinkable or what others in your chosen profession think is unthinkable was the recipe for success for Mike Collen, managing director of Diagnos.

The company, which has just expanded into new offices in Wheatley, produces diagnostic kits, called Autologic, to enable independent garages, not authorised by manufacturers' dealers, to offer an equally good service.

The sales blurb reads: "Diagnos specialises in producing high quality diagnostic tools that are designed to have similar functionality to those used by the manufacturer's dealers.

"Users of Autologic diagnostic tools are entirely independent and able to provide their customers with unparalleled service. No more waiting for dealers' workshop space. No more payment for dealers' facilities."

The business, which started in 1999 in serviced offices on the Oxford Science Park, turned over £3.3m in 2005 and is hoping to top the £5m mark this year.

It employs 30 people in the offices into which it has just moved. It has also just won the Institute for Transport Management's award for Best Diagnostic Systems for the second year running.

Mr Collen said: "It all came about when my fellow director Michael Driscoll, who was in the motor trade, found that whenever he exported Range Rovers to south-east Asia it was difficult and expensive to have the battery connected and suspension set right after the journey.

"He needed a tool that could do the job and consulted me because I was in the computer business. Then we did a few sums on the back of an envelope and saw just how big this market could be."

Seven years on and the company has made autologic kits for use with Land Rover, BMW, Mercedes, and Jaguar.

It is working on producing kits for Porsche and Audi. There are now about 1,500 kits, costing £10,500 each, in use in 50 countries.

Mr Collen explained that the company does not copy the manufacturers' equipment instead it "reverse engineers" it by analysing exactly what function is needed, and working out a way of performing it at least as well as the manufacturers'.

The joy of the system is that the software can be constantly updated via the Internet.

He said: "If customers know about cars they will understand the system intuitively."

The paradox is that the gap in the market which Diagnos is exploiting has been created by the almost Byzantine web of intrigue which was the after sales car part market, until recently.

It was the same web of intrigue which astonished BMW when it bought Rover, and then found it was not allowed to supply parts for its own cars, as that business was contracted out to Unipart.

Mr Collen said the company initially worked closely with Allmakes of Milton Park, which had been set up by former Unipart employees.

After a short spell in serviced offices, the company moved into a thatched barn in Watlington, before finding its present location.

In 2002, the European Union took steps to open up the car parts market, which in theory meant manufacturers were no longer able to lock customers into their dealer network for after-sales service.

Independent dealers were supposed to be able to get hold of diagnostic equipment from manufacturers but, in practice, they still found it hard to do so.

Mr Collen said: "There was no proper structure for supplying independents."

Diagnos has stepped in to solve that problem and now aims to match dealers by supplying training and technical support services for customers.

That means cheaper servicing on a car such as a BMW 7 Series, where there are 65 computers, controlling almost every function from lights to brakes.

Diagnos has proved to be a classic case of being in the right place at the right time to exploit a gap in the market.

Contact: www.diagnos.co.uk