Here's the thing on clay bars. Clay is a patented product which is only made by two manufacturers. For the stuff you get off the shelf it is mostly made by the same place. Meguiar's uses 'plastic' clay, but Mothers, Clay Magic, and Turtle Wax use 'elastic' clay. The Turtle Wax clay bar I bought a few weeks ago is actually really nice. I like it a lot. Typically I stick with Clay Magic (autozone carries it) but Mothers or Turtle Wax clay works too. I really haven't found to many differences from one clay to another, so I'd do whatever your wallet tells you to do if you have choices.
Beanboy, I'd have to see pictures of what you are talking about to be able to really say what to use. It definitely sounds funky...