NASCAR announced the penalty on Tuesday, saying that Newman violated Sections 12-4-A (actions detrimental to stock car racing); 12-4-Q (car, car parts, components and/or equipment used do not conform to NASCAR rules); and 12.8.1C (right rear quarter panel height did not meet the required specification; too high in post race inspection) of the 2008 NASCAR rule book.
The right-rear of his Dodge was found to be 1/8 of an inch above what is allowed.
Car owner Roger Penske was docked 25 championship owner points while crew chief Roy McCauley also was fined $25,000 and placed on NASCAR probation until Dec. 31.
"It is always our intention to follow NASCAR's rules, and we regret this mistake," Penske Racing official Michael Nelson said in a statement.
The penalty dropped Newman from eighth to 10th in the points standings.