Just to chime in...
The best way to see if you are in fact leaving behind a rotary buffer swirl or hologram free finish is you have to
chemically strip the paint and then
inspect the paint under bright light like overhead sun.
Also, this is best done on
black paint as black shows everything. It's easy to buff on a
white, or
silver metallic, or any light color and not see faint swirls left by the rotating action of the pad on a rotary buffer.
Because
'fine' or shallow swirls can be hard to see, the ultimate way to inspect would be to test yourself on a large flat panel like the hood of a car, (a car hood that's large and flat, harder to find with modern, small cars), and
then after your last step, wipe the paint down with IPA, or MS or do a Dawn wash.
Next, move the car into full on sun when the sun is bright and directly over head.
Now move around the car placing the sun into different locations on the hood and inspect for a 100% swirl free finish.
- Inspecting without chemically stripping will not prove you left a swirl free finish.
- Inspecting without using really good light, like bright overhead sunlight won't prove you've left a 100% swirl free finish.
I never see people doing this step or even talking about it let alone proving it and in the process of proving, sharing the proving process and results process.
I never see people proving their work with this step and posting
real pictures of the swirl free finish in full sun after chemically stripping. This step means taking longer to buff out any car and during the chemical stripping process you risk marring the paint and if you wash with Dawn, then you get the car all wet again, this means water in the cracks and crevices that won't dry like a flat panel so when you bring the car back inside to finish buffing it out, now the air current a rotating buffing pad creates will draw the water in the cracks and crevices into the buffing cycle.
It's a lot more complicated to 100% prove to yourself or anyone else that you are in fact leaving a 100% swirl free finish. I see people make the claim all the time but that's just their claim. As someone that has done a lot of testing on black paint and buffed thousands of cars with a rotary buffer, it's a lot harder to do than most people think and the
ONLY way to know that you have
IN FACT left behind a
100% swirl-free finish is to
chemically strip a
dark or black finish after your last rotary buffer step, move the car into bright sunlight and then inspect.
Other than that... how would you really know?
Instead of doing all of the above, simply finishing out by
"Changing the Action of the Tool", in other words, by changing over to a DA Polisher and re-polishing every square inch of the car, you
"ensure" that you've left a 100% swirl free finish and you've never worked
backwards in the process.
Wont lie. But the hologram was an up and down verticle hologram and I only went that way was with a finishing 3m polish and pad. I figured I didn't work it enough, so I drove it back in and tried it again and got it right. Just got a little lazy and rushed I guess guess the upper half of the car looked good and hologram free 
