The latest SMMT figures show a rise of 8.6 per cent in new car registrations with 462,517 registered last month as buyers continue to take advantage of a range of competitive deals.
The total number of cars registered in 2015 so far is 2,096,886 – 7.1 per cent higher than at the same point last year.
It is the first time that the two million mark has been passed in September since 2004.
Mike Hawes, SMMT Chief Executive, said: “September is traditionally one of the year’s biggest months for new car registrations, and last month set an autumn record.
“With plenty of attractive, affordable deals available on the new 65-plate, Britain’s car buyers – whether private, fleet or business consumers – were busier than ever.
“The market reached pre-recession levels some time ago, and we anticipate some levelling off in the coming months.
“It is too early to draw conclusions, but customer demand for diesel remained strong, accounting for one in two cars registered.”