first wash the car with a hose to get off the really loose stuff......
then get two buckets of hot water, one clear, one with car body shampoo
using a wash-mitt (not a sponge as that can hold grit and scratch the paint)
wash with soapy water
rinse with clear water
use the micro-fibre cloth to rinse, i don't chamois as it marks the paint
Go over the car with a PTG (paint thickness gauge) in order to see where the high and low points of the paint are
1 Mask the trims
2 Use a professional polisher (by that I mean something like a silverline orange or blue) not one of these cheap ones you can get halfords that has a woollen mitt on it.
3 Using a polish like G3 go over the entire car, taking care not to breakthrough the paint
4 once you have polished using the polisher then seal the paint using something like a carnuba wax
and finally use something like autoglym extra gloss protector
if done correctly you will have a paint finish that will look very deep
Good brief..I want to add some more points..
Using a professional polisher (I use Hitachi) always stay at the lowest
possible rpm..dont stay at the same point more than 1-2 seconds or
you will burn the paint or at least you will erase the laquer (clear coat)
and dont hurry to complete the car quickly..give breaks between the
parts..always do the polishing longitudinal to the part and use
overlapping on traces..dont forget to wet the polish head initially and
dont use too much G3 at one time..(double your toothpaste amount)
if in one point you see traces or scratches, you can use 2000
grid sandpaper with soapy water (will be easier and less risky to burn
the paint) ..And there's also a limit for the scratches to be cleared..if
you feel the scratch with your finger nail dont try to clean it
totally..Clear coat layer is tiny and in old cars risky to sand or polish
deeply..so no more than total 40 seconds of rubbing with sand paper
on a fix point(by hand)..the rest is danger zone and only for
professionals or experienced ..
Now after G3 job s finished and you see it started shining there may
be some small traces left.. Now you can do the rest with a very soft
polish head and very soft creamy wax and paste mixture..(really mix
them).. or also you can do with the hand again longitudinally..and not
using high force and with a soft cotton..
ps: never do the polishing under direct sun light..
pps : during your work,always stop from time to time (lets say 3-5
minutes) and check the paint condition