Found this link to an interesting car wax test.
Rates some new polish called Zaino's.
Zymol's cheaper polish is also rated highly and better than Meguiar's.
Think the Zymol is the same as the £12 Cleaner Wax you can get from Halfords.
Check it out :- http://www.nsxsc.com/nsexcitement/waxtest.html