UK new car registrations rose 8.2% in April to 176,820 units, the 26th consecutive month of growth.
Volumes for the year-to-date have reached 864,942, an increase of 12.5%.
The Society of Motor Manufacturers and Traders said continuing improvements in economic conditions have bolstered consumer confidence, fuelling new car registrations.
The SMMT has now revised up its 2014 market forecast from 2.3 million to more than 2.4 million registrations, a 6% rise over 2013.
"After the bumper plate-change month of March, the UK car market returned to more modest but still positive growth in April, with new car registrations up 8.2% to 176,820 units," said Mike Hawes, SMMT chief executive.
"This marks 26 consecutive months of growth as GDP continues to pick up, inflation falls and wage levels improve.
"As UK economic confidence improves still further and the market continues its upward trend, we have revised our 2014 forecast up from 2.3 million to over 2.4 million registrations. This represents an increase of more than 6% versus last year."
Sue Robinson, director of the National Franchised Dealers Association (NFDA), said: “Consumers continue to be drawn into the showroom by strong manufacturer deals and competitive finance offers. Dealers are reporting demand for smaller vehicles that offer better fuel economy and cheaper maintenance. This along with the new products and services offered by dealers and manufacturers is encouraging people to buy.
“Consumer confidence is still fragile therefore competitive pricing and strong incentives remain important in convincing customers to buy a new car.”
Chris Sutton, managing director of motor finance supplier Black Horse, said: "Whilst we anticipate a strong Q2 for car sales we do need to consider when the car sales market may level out and what manufacturers and car dealers will need to do to maintain sales momentum.
"However as long as we have low interest rates it is likely that car finance deals will remain appealing for those consumers considering buying a new car."
April's best sellers:
1 Ford Fiesta 10,250
2 Ford Focus 6,772
3 VW Golf 5,302
4 Vauxhall Corsa 3,949
5 Audi A3 3,754
6 Nissan Qashqai 3,753
7 Vauxhall Astra 3,562
8 VW Polo 3,449
9 Nissan Juke 3,053
10 Fiat 500 2,928
> For full details of April's new car registration figures go to the SMMT website.
> Brand-by-brand new car registration figures available at AMi.