NASCAR officials has discovered that the No. 48 Chevrolet had received illegal modifications on the C-posts. That's the area of metal sheet between the roof and the side windows.
Now, NASCAR authorities have decided to ship the car back to their research and development center in Concord, North Carolina, so that it can be tested further.
However, they are allowing the Hendrick Motorsports team to remodify that area to authorized specifications before practice for the Daytona 500 starts on February 26th.
NASCAR spokesperson Kerry Tharp says that officials have decided to wait until after the Daytona 500 to "address any further actions that may come out as a result of this."