Slightly odd choice for a topic around here but as we frequently deal in repair of our stuff, and usually follow "right to repair" cases, I am having it play.
Anyway it seems Sacramento, a county in California, has passed a law (an awfully worded one but more on that later) that prevents you from working on your own car, saving some "minor" works. Reasons cited for the law include property prices, chemicals polluting the environment and increased traffic (of cars that are inherently off the road...). It was however noted that as one of the things you can do is replace your oil... now I don't have the stats in front of me but I would wager serious money that most of any chemical issues as it pertains to home repair of anything running today is morons pouring oil down the drain.
Sacramento is also not one of the silly rich counties in California either in case you were thinking about that (average home price is about half LA, and a quarter of San Francisco which is not that far away as these things go).
Back to that awful wording. The list of acceptable minor repairs includes the phrase "Other similar operations" as a general phrase in a list with Brake part replacement, Minor tune-ups, Change of oil and filter, Lubrication and repair of flat tyres.
Of course one ought to hope you are not conducting it "Using tools not normally found in a residence"*. Even more fun is agricultural and agricultural-residential are included in this list -- most farmers are pretty hot at vehicle repair. Oh and if you thought you would have your mate drive over and replace his spark plugs then it would be unlawful for it to be "Conducted on vehicles registered to persons, not currently residing on the lot or parcel;". Should you be doing it outside the vehicle had better be operable within 24 hours as well, best hope you snap something and have to order it in or best to order in things that might be OK but also might not be.
*I have no idea how this would be defined. I am not aware of similar laws anywhere, and most lawmakers are almost allergic to that level of vagueness. More amusing still is most of the apparently acceptable list (ignoring how much you often have to strip down on a lot of modern vehicles to do some of those) have tools I would not expect to find in normal residences -- the video at the start brings up the general lack of oil filter housing spanners or strap clamps. I had a quick look at the walmart tool section and that does get me a 3/4 inch air powered rattle gun sporting "1600 ft-lb Maximium torque" (looking at the compressors they will also sell me I am probably going to get 2 seconds of use between compression cycles, and I don't know what I am getting by way of impact sockets, but that is OK), if I am allowed harbor freight (I checked and there are some 6 of them listed in Sacramento, more in the immediate surrounding areas) then all bets are off. Home Depot (7 of them in Sacramento I think) will apparently also sell me a 12000 lbs (5400 or so KG) 4 post vehicle lift capable of doing wheel alignments, and a nice complement of bearing pullers should I decide to do that while I am in there. Could also do a new brake line with the flaring kit I got at walmart (we are even specifically allowed to do "brake part replacement").