Supercars announced on Tuesday testing had shown the Mustang held an unfair aerodynamic advantage over its Holden and Nissan rivals.

The championship has ordered alterations be made to the car ahead of next week's event in Perth, mainly to the vehicle's rear wing.

Rivals have long claimed the Mustang held an unfair advantage under Supercars regulations which prevent significant disparity between competing cars.

Led by DJR Team Penske star Scott McLaughlin, the Mustang has won nine out of 10 races in 2019.

Bowe said the situation bore similarities to his championship winning year in 1995 when the undertray of his Falcon had to be trimmed ahead of that season's endurance events.

"Just goes to show that the squeaky wheel usually gets the oil," Bowe said on his Facebook page.

"I'm a racing and car guy, but this sort of thing going on in the midst of the season makes a mockery of the series.

"It reminds me of 1993 and 1995 when the whinging (sic) from Holden had changes made mid season. I[?] would have thought that sort of thing would be well and truly behind us. Alas, no!"

Bowe believes the changes won't stop McLaughlin's dominance, saying it's more than a slight aero advantage behind the defending champion's 2019 form.

He did however have questions for Supercars measurement of aerodynamic performance.

The upcoming changes are the second alteration forced upon the Mustang in 2019 despite its initial specification being signed off in December by Supercars and the three teams responsibile for vehicle parity - DJR Team Penske, Triple Eight and Kelly Racing.

"It's now time to adopt a proper process," Bowe said.

"Genuine real live wind tunnel testing in the USA so this bunfight does not happen again!!! Ever!!

"In a category that makes and spends millions of dollars every year, the cost of air freight for 3 cars to America and some wind tunnel time is a drop in the ocean."

Australian Associated Press