Sales at Orange County auto dealers rose in April, up 13.5% to 10,198 autos from a year earlier, according to the Newport Beach-based Orange County Automobile Dealers Association.

The figure is based on registrations with the state, a barometer of sales.

Dealers have had at least eight consecutive months of sales growth.

Still, April’s auto sales were below the 14,994 autos that dealers sold in April of 2006, when the market was stronger.

South Korean automakers Hyundai and Kia, which have their U.S. bases in Orange County, continue to boost sales in OC.

Hyundai was up 34% to 615 autos sold. Kia was up 69% to 315 autos.

Luxury car sales improved for all of the major brands, except Lexus, hurt in part by the earthquake and tsunami in Japan.

Mercedes-Benz was up nearly 14% to 659 autos for April. BMW was up nearly 37% to 528 autos. Lexus was down 20% to 373 autos.

Porsche was up 20% to 54 cars. Jaguar sales were up 52% at 29 autos.

Japanese automakers Toyota and its key rival Honda had mixed sales. Toyota was down nearly 11% to 1,840 autos sold in April.

Honda boosted sales nearly 30% to 1,702 autos.

Among the domestic brands, Ford’s sales rose 25% to 758 autos. GM’s GMC brand was up 35% to 131 autos.