This paper examines labour transnationalism within four multinational automakers. In our sample, we find different forms of labour transnationalism, including transnational collective bargaining, mobilisation, information exchange and social codes of conduct. We explain these differences through the interaction between management and labour in the context of the company structure; of particular importance are transnational coercive comparisons by management and the orientations of worker representatives as political entrepreneurs or co-managers. We conclude that, although intensified worker-side crossborder cooperation were not preventing wage-based competition in general (due to the lack of between-firm coordination), they have reshaped employment relations within these MNCs.