There's all sorts of products out there end of the day it all depends how well ur paintwork has been prepped as in removing swirl marks and light scratches,the way I see it is by waxing or using a sealent won't make the car shine its simply sealing up your paint,for instance if u wax a car and it looks alot shiny u have simply just filled scratches up some waxs and sealants contain filler so ur not removing these scratches,so in terms it's how you polish to prep the paint you could use a £100 wax or a £5 wax if it ain't prepped well then you'll never get that shine and protection,idearly you wana prep the paint with one of the 3m pads with a buffer which gives a slight cut into the paint and also an easy pad to work with,as for a polish you'll need a really light abrasive one to match accordingly to the pad and also the condtion of the paint, so many products out there it's just all trial and error for the go.