More than half a million new cars were sold in March in the strongest month in the UK since 1999.
The Society of Motor Manufacturers and Traders (SMMT) said almost 519,000 cars were registered as sales grew 5.3%.
Sales of alternatively fuelled vehicles jumped 21.5% year-on-year, with diesels and petrol cars up nearly 5%.
March is typically the biggest month, accounting for around a fifth of the year's car registrations.
The sales figure is the highest since the UK moved to a new system in 1999 that meant new number plates were issued in March and September each year.
It is second only to August 1997 when 525,539 cars were sold.
Mike Hawes, SMMT chief executive, said, "The sector's strong growth in March rounds off a robust first quarter as British consumers continue to demonstrate their appetite for new cars, especially ultra-low emission vehicles."
Almost 770,000 new cars were registered in the first three months of the year.
The top selling models in March were the Ford Fiesta, Vauxhall Corsa and Ford Focus.
The UK car industry has been growing for four years in a row, helped by cheaper finance and stronger exports.