Dennis Bass has not just got the only car of its type in the world but he also owns one of the most sought-after registration plates.

The Renault Park Phaeton, built in 1905, carries a price tag of £100,000 but despite its history many are more interested in its number plate.

The registration AA1, is one of the world's most sought after and worth an estimated £250,000, more than double the price of the £100,000 car.

The car, bought owned the Automobile Association, was orginally registered OPL 839, but when the organisation were offered the number plate AA1 they bought it for the Renault.

As the interest and market in personalised number plates has grown, AA1 is worth more than the car.

The Driver Vehicle Licensing Agency in Swansea said: "We sold 1A in 1989 for £200,000. Predicting the value of number plates is not an exact science, but AA1 would be one of the most sought after if it came on the market.

"It was issued between 1904 and 1917 and is the prefix for the Salisbury and Bournemouth area."

Dennis, a Seaford businessman and advanced driver, keeps the car locked up in a secure garage and only allows it out on special occasions.

He knows the width and breadth of the vehicle as if it is his own body and has learnt to use the car's leather clutch and quaint gear and breaking system.

Dennis, 56, said: "You have to get to know this car. The brakes are virtually non-existent because they are rod brakes and only apply to the rear wheels. The breaking system is like constantly putting on the handbrake. Sometimes you have to steer with one hand on the wheel and the other on the handbrake.

"You have to concentrate all the time. It really is a magnificent vehicle even if it is not a smooth ride and you sometimes get wet."

The car, with its gleaming maroon bodywork and brass trimmings, was the pride of Renault when it left the works in Paris.

It was owned by members of the Paris gentry for years, once belonging to Lady Cheylesmore, lady-in-waiting to Queen Mary. President General de Gaulle has also ridden in it.

Despite its finery the Renault was neglected for years because it was only ever used for occasional outings.

Veteran car enthusiast Paul Waring, who lived in Hampshire, bought the vehicle in 1954 and started restoration work.

When he and his young son were killed in a motor accident, his mother got in touch with the Veteran Car Club of Great Britain, to find the car a good home.

The AA bought it to celebrate their 60th anniversary in 1965.

They chose Dennis, a man who can, and does, look after the organisation's pride and joy as if it is his own.

Dennis, who was then leaving the AA to run his own data systems company, still regularly makes trips to Basingstoke where the car is secretly garaged.

He said: "I do all the routine maintenance, check it over and ensure everything is working well for each trip. You have to be totally dedicated to keep a car like this."

The car is rolled out for special events, with AA staff with more than 20 years of service being allowed to use it for family weddings.

Special dispensation allows the car to take part in each year's veteran car run to Brighton. The run is for cars registered before 1905 but the Renault is allowed because there is evidence it was built in 1904.

It is always the last to leave the start at Hyde Park in London as the oldest cars are allowed to set off first.

Wherever it goes Dennis, sometimes in genuine chaffeur's uniform, is always at the wheel.