Please dont use 'Polish' as a term for waxing your car or applying a protective coat (Paint sealers).
Polish contains abrasives and should only be used to remove swirls and surface contaminents.
Sorry to sound so pedantic.
DONT BUY any of these coatings from a dealer.
They are on MASSIVE commission.
If you really want them, go on eBay, buy there for £10 or less and apply it yourself.
This is the best site Ive found for advice:
www.polishedbliss.com