Rear Suspension Leaf Spring Leaf problems of the 2004 Chevrolet Colorado

(1) intermittent noise from rear suspension: may be relevant (2) while driving at freeway speed on I-15 south, north of san diego, CA, heard noise; managed to drive truck (2004 chevy Colorado) to nearest exit, coasted to a stop. All the while, the truck vibrated violently and I barely avoided crashing into other vehicles. A chevy dealership located nearby inspected the truck, determined that rear right side leaf-spring broke at eye and entire drivetrain suffered subsequent damage as the truck was driven for several miles with the leaf spring broken (3) gm area service manager refused to cover the repair under warranty, stating that "usual cause is impact related". Gm and dealership categorically refused to advise the owner in writing reason for warranty coverage denial. Owner requested in writing, before authorizing repair, that old parts be returned for the specific purpose of failure analysis as owner suspected manufacturer or installation defect. Dealer promised to save old parts but when owner was advised that repair was completed on 5/31/06, the dealer advised that old parts were lost. Owner suspects foul play, intentional destruction of evidence. Later, dealer's employee mislead small claims court judge about destruction of old parts. California department of consumer affairs cited dealership for failure to return old parts, case mr-2006015137, phone: 951-782-4263. Updated 03/13/07.