CONCORD, N.C. -- Haas CNC Racing's two qualified Sprint Cup cars for Sunday night's Coca-Cola 600 were confiscated by NASCAR on Saturday afternoon and taken to its nearby research and development center.

NASCAR spokesman Kerry Tharp said the sanctioning body had "an issue with the upper rear wing mounting points of the 66 and 70 cars."

Tharp said the Chevrolets -- the No. 66 driven by Scott Riggs, which qualified in the 13th position, and the No. 70 that was qualified in the 43rd position by Johnny Sauter -- had an "altered location of the upper wing mounting point."

NASCAR issues the main wing elements to the teams at the racetrack each weekend, but the teams install the mounting brackets themselves.

"The discrepancy was brought to our attention, and we addressed it," Tharp said. "The garage is a self-policing area. We follow-up on information we get [and] we're always inspecting racecars. That was the case with this."

Tharp said the teams would use backup cars for Saturday afternoon's two Sprint Cup practice sessions; and the teams would drop to the end of the inside line of the grid for the start on Sunday evening.

Tharp said NASCAR would announce the results of its inspection next week, per its usual procedure.

Last year, the No. 8 Dale Earnhardt Inc. Chevrolet that was driven at the time by Dale Earnhardt Jr. was found to have unapproved rear wing mounting brackets at Darlington. The team received monetary and points penalties and crew chief Tony Eury Jr. was suspended.