When you start out with your 320 grit do you use a medium pad and then change to soft for the 400 grit or is it a soft pad all the way?
no 320 bro
400
as PC said
start with 400 then 600 dry
change paper frequently as not to burn or scuff
I use a soft pad for all
if the sand coat is primo the gloss coat will follow suit
if not , expect wavers
use good polishing juice
if you start with 320 you will miss spots when changing grits and have sand throughs
and you will be back pedling
edit: do the nose and tail by hand
more than one way to skin a cat - everyone has a different method.
there are multiple threads where all the gurus share their detailed sanding/polishing techniques.
i like a harder pad and some 320 to get everything leveled off nice before polishing.
to go straight to 400 on a soft pad - sand job and gloss coat have to be spot on!
320 to slow
400 get it flat without scratches