I do the automatic wash at the local Petro Canada. I buy a book of 7 washes on a card and that works out to around $12 CAD each. I Krown and do my own touch up with various RI products, whatever is thick, well respected and on sale.
IMHO, there is no perfect solution for most Canadians or Rust Belt America, you store it outside, the engine & drivetrain feels the cold, but the body lasts longer. I keep mine in a garage with my wife's car and my motorcycle. I don't heat the garage but the place never really gets any lower than +3C so my engine warms up fairly quick. With the recent supply chain stuff and the trend for OEM's to stop carrying parts past 10 years, what will be our situation with non rusted but obsolete 10 year old cars?