When I first purchased my Infiniti G37 in 2010, it was a shiny new black. Infiniti was touting their self healing paint. They did not stick with that for long. But...wanting to keep the look right, I set about trying to learn more about car paint care. I grew up washing my parents cars with dish soap from a bucket...so I needed to something better.
I wound up going to Detailed Image. Bing, DuckDuckGo, or Google that company. It will take you to a site that sells all kinds of products. The great thing about this site is the support. They have an ask the pro tab and a detailing guide tab. If you go to the detailing guide tab, it has how tos on everything about car cleaning. The other thing the site offers are reviews of products and you get to see what the pros are using.
I followed their instructions and recommendations for the car wash, exterior detailing, and interior detailing and it kept my G37 looking nice until I had a "professional" do a wax job on it...big mistake there. It looked great when I picked it up, but after the heavy wax came off, swirls were all over the place.
There as one product that they had that allowed you to do a rinse-less wash. This meant with a couple of buckets, you could wash your car in the garage in the middle of winter and stay warm. I liked that one.