I was born and raised in LA, so I know the California Accent very well. And yes, "Spanglish" is very common in California. Like seeing ads stating "Cerveza en venta - 6 Pack"
And we do have a particular dialect. The vowel shift, and how we say some things is very specific only to California. But more common, what tends to make it stand out is how we pronounce the Spanish words we commonly use.
It is not uncommon to hear outsiders call a major street "Rodeo Drive" completely different than we would. Or saying towns like "La Cañada", which most not from the area will call "La Canada". Or give an outsider directions to go to "La Brea", and unless they had heard a local say the name will say it wrong. El Cajon, La Mirada, Cahuenga, local see that and are much more familiar with the Spanish pronunciations than most outsiders, even if they do not speak Spanish.
And of course, then you have the simple aspect of having us describe freeway directions. That is a sure fire way to identify a Californian. And until recently, from Southern California only.
But even then, the accents shift. In the 1980s I lived in North Carolina, and picked up their accent. Which tends to be a slower drawl than other areas of the South (think Andy Griffith). And in the 2000s, I lived in the Wiregrass (SE Alabama), where the accent and speech tend to be much faster than in Carolina (but if you move to the East into Georgia it slows down again). Then after that, the more "Twangy" accent of Texas. I know that a lot of people can't actually identify accents past a very simple level, Virginia, Carolinas, Tennessee, Mississippi, is all "Southern" to them. But I guess traveling as much as I have in my life made me more sensitive to them than others.
