I'm with Z4 Beemer on this one, but instead of Swissol I use Zymol
They're both incrediby good wax brands which will beat ANTHING you can buy in halfords. Yes they're expensive BUT the results show and given just how little of the stuff you actually use, you certainly won't be buying more wax in a hurry!
Zymol gives what I'd call a "wet" look to the finish. The paint looks almost 3 feet deep when you've finished and the way it throws off water is just incredible.
One thing to keep in mind though is that because these are natural waxes (which smell fantastic) they're not as hard wearing as modern synthetics. So, get some Maguires Polish as a first coat and then add the Zymol/Swissol for its incredible finish!
I've attached a pic of my old Z4 (sob) after just one coat of Zymol.