NHTSA opened a defect investigation last year after a consumer complained that the back glass window of the convertible top separates from its adhesive bond attachment to the convertible top material.
Federal safety regulators said they received 212 complaints about the problem, but there were no related crashes, injuries or fatalities.
"NHTSA's review indicates that separation of the back glass occurs gradually and the glass remains intact and inside the top after the failure," the agency said in a Tuesday posting on its Web site.
"Considering agency priorities and agency resources, and the likelihood that further investigation would not result in a defect finding, NHTSA has concluded that further investigation of petitioner's concerns is not warranted."
Edmunds says: Since this petition is denied, owners of these cars do not need to take any action. But if you still have a concern, it's best to contact your Chrysler dealer.