I argue, in this case study of Tianjin's auto industry, that informal institutions and processes result in effective negotiations and substantial outcomes, even though formal institutions - employers' associations, industrial unions, autonomous unions in workplaces, and a legal basis for strikes - are either absent or not providing favorable conditions for collective bargaining in China. In particular, I have found that spontaneous wage coordination amongst employers and amongst unions have occurred and imposed wage constraints to individual firms on the one hand, and on the other, some firm unions have actively engaged in informal negotiations to challenge the wage constraints as well as appease discontented workers. I also discuss causes, mechanisms, and effects for each of the two levels of informality.