Here is what I do to get my Z4 ready using Zaino products:
Wash thoroughly with Dawn
Clay bar entire car
Wash again with Dawn
Zaino PC Fusion (using a Porter Cable) if you have loads of swirls/towel scratches. If not, skip Fusion
Zaino AIO (again using a Porter Cable)
Z5 Pro (
very light application with ZFX accelerator)
Z2 Pro " "
Z5 Pro " "
Here is the Zaino link with a longer winded explanation:
Zaino
I believe using a Porter Cable applies product more evenly on the car no matter what product is used. I wash using warm potassium softened water, a boar hair brush and dry my car using a high powered leaf blower. I use a waffle weave drying towel to finish the drying process.
On the other hand....
Just this weekend I did a more thorough job of removing some pesky towel scratches and other surface problems. (btw, these can occur using even the best towels.) I used the old fashioned (and very very effective) method of removing (knocking down) 99.85% of all the swirl and other scratch marks. I wet sanded (1500/2000 grit) a small area then used a series of aggressive to mild compound product starting with wool pads to polishing foam pads to achieve a mirror finish on my Sapphire Black finish. I used Meguiar products for this initial cutting going from aggressive to mild, 3M Protect-it Glaze topping off with P21S Carnauba Wax. I did this to prep for what will be a very competitive car show season. This process is usually on done once every few years (for me, at least). It takes loads of labor and technique and unless you are going to compete is only for the truly obsessed. On the other hand, one could always pay a professional car detail to do this work for them. It wouldn't be the same, however. There are loads of product out there to use, some good, some are junk. The bottom line is to use a proven product with a proven procedure/process. Either way it is very labor intensive. The rewards can, for some, achieve nirvana level.
Then there are windows to clean.

I'll leave that for another thread.