The jury had assessed substantial punitive damages against Chrysler, which the Tennessee Supreme Court upheld after a substantial reduction. The United States Supreme Court (at least no more than a few of the justices) apparently thought the decision did not need to be disturbed.
As a reminder, a little boy died because of a defective seat in a Chrylser minivan that failed, fell back on him, and killed him in a car accident. The link in the July 5, 2008 post referenced above has all of the necessary background information about the case.
Here's a link showing the denial of cert:
This is a very tragic case. However, at least the family was not denied some justice for their loss.