Hyundai Motorsport was hit by a massive €50,000 fine late on Sunday after admitting fitting the wrong rear side windows to Rally Italia Sardegna winner Thierry Neuville's car.
Neuville faced an anxious wait to see if he would keep his win after event Stewards investigated a report from FIA Technical Delegate, Jérôme Touquet, following post-event scrutineering.
Team boss Michel Nandan admitted the windows on Neuville's i20 were not the same as those submitted in photographs in the homologation form.
He said the illegal windows had been used in all their 2016 cars since January's Rallye Monte-Carlo and accepted they made a mistake in the homologation process.
Nandan explained that the windows shown on the homologation form could not be fitted into the rear doors of the finished car. The car was originally presented for inspection with the doors unassembled and the team did not realise that the windows could not be fitted into them.
Stewards were told the new windows were 17g lighter on one side and 19g lighter on the other.
Nandan declined to comment on the decision but wrc.com understands that the team will not appeal.