No water mixed with the oil? Check.

Interior clean? Check.

But wait, there's a dent in the rear of the truck Miguel Alfaro is appraising at Zumwalt Ford Mercury auto dealership in St. Helena. The dent will put a dent in the appraised value of the truck, Alfaro said, marking the flaw on his checklist.

Appraising cars is one of the many tasks for Alfaro at the dealership where he's worked for the past 10 years. His bosses say they love him and so do his co-workers. One of his co-workers sort of has to -- he's Miguel's brother, Ed.

Together, the Alfaro brothers comprise Zumwalt's "Hispanic Dynamic Duo," helping establish an Hispanic clientele accounting for 30 percent of the dealership's sales.

But that wasn't always the case. Before Miguel Alfaro began selling cars, Hispanics accounted for about 2 percent of the dealership's sales, said Scott Zumwalt, co-owner of the dealership.

Before the duo came on the sales scene, when someone who spoke only Spanish wanted to buy a car, Zumwalt said, "I had no one (to talk to them). We dealt with their kids."

That strategy changed with Alfaro's promotion from the parts department in 2000. His ability to speak Spanish, coupled with his understanding of the local Latino culture, helped boost business at Zumwalt.

"When I am selling a car to a Hispanic person, I can talk to them in their language and I know what they are looking for," Alfaro said. "Just the fact that I speak Spanish, they feel more secure about what they are buying."

According to Zumwalt, Alfaro's promotion into sales caused such a spike in the number of Latino clients that the dealership needed to hire another Spanish-speaking salesman.

In 2001 Zumwalt hired Ed Alfaro. Ed Alfaro said he had it tough when he first began selling cars alongside his brother.

"It's hard to start because you have to build a clientele," he said. "(Now) I'm getting a lot of repeat customers."

Se habla Espaol

Zumwalt is just one of the dealerships in the valley that has tapped the Hispanic dollar by using bilingual sales staff. Vince Compagno, owner of Napa Nissan, said he has two bilingual salesmen ready to help customers in Spanish and English.

"It has definitely increased the business," he said.

Hispanic customers account for 30 percent or more of Napa Nissan's sales. In any given month, the dealership sells about 100 new and used vehicles, he said. Compagno said it's important for his dealership to communicate with Spanish-only speakers because of the prevalence of Nissans in Mexico.

"There is loyalty in their country (towards the Nissan brand)," he said.

Keeping it real

Zumwalt's Hispanic Dynamic Duo don't just talk the talk. They know the cultures, Latino and Napa, they need to know.

The Alfaro brothers were born and raised in St. Helena. Miguel, 30, graduated from St. Helena High School in 1995. Ed, 26, graduated from St. Helena High in 1999.

Their parents, Miguel and Alicia Alfaro, came to St. Helena in 1968 from Atacheo, Michoacan, Mexico, and raised their six children in the valley. Every two years, Miguel and Ed visit Atacheo.

"Basically, we just go back to our hometown. My parents own a home down there," Miguel Alfaro said. "The reason I go back is to take my kids down there and see where they came from and see the tradition and culture."

Three years ago Scott Zumwalt said he wanted to see the "real Mexico" and flew down to Atacheo to join Miguel. Once in Atacheo, Zumwalt said, he saw many St. Helena residents and got a better sense of what the culture is about. In 2005, Zumwalt made a second trip to Atacheo along with Miguel.

"It makes me feel that he cares about us ... (and) not just doing business," Alfaro said. "It just makes us feel that we are part of his family."