One of the local TV stations brought this up, I did not hear the story, but found the following:
http://www.detnews.com/2004/autosinsider/0411/10/a01-328287.htm
From that article:
Volkswagen AG, BMW AG, Toyota Motor Co.p. and Mercedes-Benz warn U.S. consumers about aging tires.
In its owner's manuals, Volkswagen warns motorists that old tires can fail in use, causing loss of vehicle control and personal injury. They are advised to replace tires after six years, regardless of wear.
The tires on my SLK will 'never' last six years, I drive it often and hard enough so that they wear way before that. Car is going on being 8 yrs young, and I am on the 3rd set of tires. BUT I do often keep mismatched tires in the garage to keep as temp spares, if needed, while waiting a day or two or for ordered 'tires'. I even kept 2 of the Mich Pilot Sports from the SLK for 'temp' spares. They had enough tread on them to be 'legal' in PA, but not enough to track the car last summmer.
I understand that some tires already it, but it is NOT a 'easily' readable date.