When Honda said late last year that it would no longer use Takata as supplier of its airbags, the Japanese automaker admitted that the data collected from testing the airbags had been misrepresented and manipulated. This has been shocking to the public and the many local Honda car owners in the US.

For example, “Happy Manipulating!!!” was what one a Takata airbag engineer wrote in an email from July 2006, in a reference to results of airbag tests. In another email, he described changing the colors in a graphic to divert attention from the test results.

The emails were among many documents unsealed as part of a recent personal injury lawsuit against Takata. Takata said that the exchanges had to do only with the formatting of data and were unrelated to the defective airbags under recall.

Takata’s airbags have been linked to eight deaths in the U.S. and more than 100 serious injuries from explosions. This has caused the recalls of nearly 20 million vehicles. Regulators have said that millions more airbag inflators may need to be recalled unless the company can prove that the propellant they use is safe.

While Honda hasn’t commented on whether the emails were definitively evidence of wrongdoing, the automaker said it came to its conclusions following a review of millions of internal Takata documents. Four airbag experts asked to review the emails, who agreed that the emails showed the misrepresentations of testing data.

Takata’s practice of manipulating airbag test results dates to at least 2000, around the time the company introduced a new type of inflator.