"What that $70 figure (or $73) actually represents is what it costs GM in total labor expenses, on an hourly basis, to manufacture autos.
Do you see that there's a big distinction? General Motors doles out $70 an hour in overall labor costs to manufacture cars. But individual employees don't get paid $70 an hour to make cars. (The discrepancy between costs and wages is explained by additional benefits, pension fees, and health-care costs GM pays out to current and retired employees.)
Simply put, GM's labor costs are not synonymous with hourly wages earned by UAW employees. Many in the press have casually used the two interchangeably. But they're not.
Felix Salmon at Portfolio did perhaps the best job explaining the misinformation at play:
The average GM assembly-line worker makes about $28 per hour in wages, and I can assure you that GM is not paying $42 an hour in health insurance and pension plan contributions. Rather, the $70 per hour figure (or $73 an hour, or whatever) is a ridiculous number obtained by adding up GM's total labor, health, and pension costs, and then dividing by the total number of hours worked. In other words, it includes all the healthcare and retirement costs of retired workers. [emphasis in original]"