Los Angeles is one of the most Hispanic cities in the country, with 48% of residents self-identifying that way in the 2006-08 ACS, but when it comes to correctly pronouncing Spanish place names, Metro's in danger of failing Spanish 1.
Take the San Pedro station on the Blue Line. In Spanish "e" makes the sound of "a" in the word "pay" or think the Fonz says "¡e!". So the correct pronunciation is "sahn PAY-dro" (Saint Peter). Metro's electronic voice pronounces it incorrectly as "sahn PEE-dro".
Another instance of the same mistake is the pronunciation of the Mariachi Plaza station name on the new Gold Line extension. The correct pronunciation is "Mah-ree-AW-chee PLA-sa", but the electronic voice mispronounces it as "Mare-ee-AW-chee PLA-za". In Spanish there is no "z" sound. The "z"s are pronounced like "s"s.
On the other end of the Gold Line there's the Sierra Madre Villa station. Metro does okay with this except for the last word. In Spanish two "l"s together make the sound of a "y" so the correct pronunciation is "VEE-ya" not "VIL-a".
Is this really that important? A lot of your riders speak Spanish, and mispronouncing words gives the impression, fair or not, that you are out of touch with your riders. I know you have Spanish speakers on staff. I'd really consider changing this. Pronouncing words correctly is a sign of respect to your riders and to Hispanic heritage. People will notice and say, in whatever language, "wow, they took the time to get that right, maybe they'll listen to me if I have a complaint".