My plan is DIY ceramic for about $50 and 1/2 a day of labor, but that's certainly not the minimum. I may never get to the ceramic with the way I' starting to dislike tesla.
The bottom line is the more time and care you take the better.
2 bucket method is good if washing with a hose!
I find it a bit overkill if you have a foam cannon and pressure washer though, pretty much becomes the one bucket method. Unless you use the second bucket for wheels, but my first bucket is usually pretty clean still as your blasting off most of the gunk with the pressure washer.
This guy has some good tips (you don't need to follow everything, or buy crazy expensive AMMO products).
I did a quick wax on my tesla today, there's so much glass and the car is small so it really does not take too long. Under 2 hours.
Cleaning the interior glass is going to be the hard part! the 3 towel method works really well. I bought some expensive glass towles but haven't got to using them yet. I think the cheap yellow costco ones I got work fine for glass though.
This towel is very soft and I was able to dry my entire car with it. I think it's a keeper. Although I guess I have to find a way to wash it after every or every other use?
I also have an absorber which works great for my non tesla cars. I just wash it by hand after every use and put it back in the box because you store it wet!
https://www.amazon.com/gp/product/B01BD5F19A/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
I think it's better to pay for a partial PPF than ceramic even if it costs more. Ceramic works like a longer lasting wax.
Minimum should be the two bucket method, plus an occasional wax, but again the more you put into it the longer it will last.