It’s not so much that they never show up - it’s that Cardinals are sufficiently rare in California that birders take notice when they do show. For example, the Orange County Birding List noted when a Northern Cardinal was found in Fullerton, CA from June 7, 2016 to July 5, 2016 (https://calbirds.com/?board=orangecountybirding&text=northern+cardinal) - when a bird as rarely found as a Northern Cardinal is seen in California, people head out to find it, and chat with each other about it on the local rare birds site. Disappointed messages of ‘I couldn’t find the N. Cardinal in Fullerton today’ will start showing up once the bird is gone.
If you do have a Northern Cardinal, and are in a populated area, chances are someone on your local birding list has noticed. If you’re in a rural area, it’s possible no one has seen it yet - but the more time it hangs out there, the more chance there would be that someone would notice it and talk about it online.
Check your local birding list for your part of California, and see if anyone’s talking about Northern Cardinals in your area… http://digest.sialia.com/?rm=all_lists
There is a small section of extreme southeastern California that has Northern Cardinals living in it regularly (near Needles and Palo Verde*, CA) but in Northern California they’re pretty rare.
I live in the SF Bay Area, in the East Bay. Fairly urban, but lots of trees, parks, etc. Most houses have yards, though they’re usually divided into multi-unit housing these days.
Yes! Gonzo has a husky voice. The bird will swoop by, and go “EEEEEEE!” It may rise in pitch a tiny bit in the middle, but it’s more or less one tone. It sounds like a human being, not a bird at all, but it’s definitely coming out of something flying. I believe once I heard it called by one bird and answered by another.