... the distances between campgrounds was never much more than about 100km or 60 miles.(ish)
... You will notice that there are lots of panhandlers, people asking for money, the climate of california means there are more homeless people in general, so just be aware and being from London, just use your common sense of being aware of your surroundings....
... having a mirror is especially important ...
Agree on the campgrounds. We planned to motel it about one out of three nights, but we have exceptional weather and only stayed in a motel once, that was in Eureka where there were not many campgrounds to stay at. (There was a KOA near Eureka, but after state parks, we were not enthusiastic about a KOA.)
We also saw a couple homeless staying in the hiker biker sites, prevalence of that increased the further south we got, I suspect that was because it was drier further south. A couple times I mentioned them to park staff, once they kicked them out of the park.
Mirror, totally agree. The guy I tour with uses one that clips onto his sunglasses or regular glasses. I use a Third Eye one that clamps onto the visor of my mountain bike type helmet, but it only works on the left side of the helmet (we drive on the right side) so if you got that it would be worthless to you when you get home. The one I use is called the: Third EyeŽ Hardshell Helmet Mirror (03) at:
Third EyeŽ Mirrors