The March '13' registration plate has been the most successful, outselling all previous six month plate runs since September 2008.

The Society of Motor Manufacturers and Traders revealed the 13-plate has, up until the end of July outsold nine registration plates - even with August still to be included. It has been registered to 1,115,459 vehicles since March.

The SMMT forecasts around 390,000 63-plate registrations in September.

This means around £6 billion is expected to be spent on new cars as motorists take advantage of affordable finance deals and buy into better fuel efficiency, predictable maintenance and often lower tax bands, says the SMMT.

“We have seen a strong performance from the new car market throughout 2013, with the number of cars registered increasing in July for the 17th successive month,” said Mike Baunton, SMMT interim chief executive.

“Now we have evidence of consistent growth, we have raised our forecast for 2013 new car registrations to 2.216m units, an increase of over 8% on last year.  In line with this positive trend, we expect the new 63-plate to be very successful and for September registrations to provide a similar peak to that seen in March.”

March is typically the month for the highest number of registrations, with September coming a close second. More than a third of annual registrations occur in March and September combined, with the other months typically accounting for 6.5% of the annual total.