hiya 77CVT , first one is don't try to get a better polish with those BLACK polish crappola u bute polishes there more like polish strippers than enhancers.started off with prepsol/polish remover . Scared the crap out of me cause it sent my paint /car section grey.Then went to 2000 wet and dry lottsa water with a plastic block but just got stuck on duco.Best result for first stage after prepsol to remove swirls and light scratches was to use 4000 wet/dry/water sanding pad with plastic block,lottsa water and just glides over the surface made the whole process easier,still hard work but really made the basis of a good polishing process something to build on.Then came my DEWALT 849 polisher set on 1000 rpm with a good lambs wool pad,System One Polishing Compound shady cloudy cool day finished about 5 PM took me 5 hours for the first step,then came yellow pad on the dewalt and system one polish took me nealy all second day.Third day was system one polish with a finshing Black foam pad.then a special sponge with polish , finally buffing whole car with a open weave polishing towel/wipe. After that Maquires Canubra WAX,all in all with rest brakes cause the buffer aint't light it took me four days.I wish I hadn't started with the 2000 wet and dry first cause the 4000 with the pad is so effective and takes all the swirls out if your just patient and don't rush the job.I'm a bit of a perfectionist so it took a bit of practice with the buffer on the last to stages to realise your buffing the polish ON...........I was pushing to hard even on 1000RPM and was burning the polish on, so you don;t need to search for a killer shine at this stage.....you should be just trying to leave the polish on as they say.IN the end I found out to get a killer shine on black cars comes in stages, A great polish,Magiures or mothers,a great buffer<variable speed is a must and I did mine on cloudy days so I could see my progress better. If this helps I'm real glad because my shine is truly trial and error. ;);););)