Wash it once or twice a year. Change oil regularily. usually blow off the owners manual maintenance because I think they over do it. Like engine flush and changing your transmission fluid and filter every 20,000. I used to do the flush myself wuth the Prestone kit until I learned just how bad the antifreeze was to kids and pets.
I don't know if you remember but that kit came with a hose connectioon that you hooked directly into your heater hose and a discharge connection that replaced the radiator cap. You just flushed into the driveway.
BAD.....VERY BAD...
I had it done on my wife's car at 45,000 and sold it at 96,000. Did the transmission once, I think at 60,000.
I'm not good at it, but the cars are built better these days and can go longer if you don't drive them like an idiot. I know I should be better at doing the recommended, I just don't have that kinda cash. Those recommended maintenance actions are bread and butter to the dealers.