I think the OP is referring to LA county unincorporated area. Not in a city such as Pasadena-which have their own regulations.
Unincorporated land is diverse in LA county-stretching all the way to sparsely populated deserts. Probably the level of enforcement of these regulations is highly variable due to location, population density, and whether a neighbor decides to complain.
If it was me and trying to decide where to park my motorhome, I'd scout the neighborhood. Are there other RV units parked on the driveways? How would RV fit in parked there? Your immediate neighbors? Are you in such a rural area that few would see it or care? I'd always have fallback that it may be necessary to move to paid storage.
