While GM maintained its world leadership in revenue and market share throughout the 1960s to 1980s, it was product controversy that plagued the company in this period. It seemed that, in every decade, a major mass-production product line was launched with defects of one type or another showing up early in their life cycle. And, in each case, improvements were eventually made to mitigate the problems, but the resulting improved product ended up failing in the marketplace as its negative reputation overshadowed its ultimate excellence.