Legal Notice Class Action Suit in CA against GMC for Engine Knock Noise

Received this in the mail yesterday from The Garden City Group INC:
Starts out:
TO: All California owners and lessees of 1999-2003 Chevrolet Silverados
equipped with 4.8 5.3 6.0 or 8.1 L engines
It has to do with that knock ping or slap noise on cold engines that goes away in a few seconds (I get it on mine). The suit claims GMC's unspoken "Engine Knock Noise Adj Program violates California's Secret Warranty law.
They have a web site:
"Their line is gone out through all the earth and their words to the end of
the world."
  Click to see the full signature.
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