Hey,
Clay really does work, but you must be careful how you use it. Be sure to constantly keep spraying the area with copius amounts of soapy water from a Spray Bottle as a lubricant.
So far as other Car Care Products, well this is akin to the
Boxers vs Briefs debate - it's totally a matter of personal preference.
Personally, I use Zaino Bros. and have exclusively for 10+ years. My
Black Lotus Esprit won every Show it's ever been in, including the Concours D'Elegance at a National Lotus Convention, so Zaino's been working for me. Check it out at :
http://www.zainostore.com/ , or:
http://www.nsxsc.com/nsexcitement/waxtest.html. Then make up your own mind.
Happy Motoring!... Jim'99