There are a lot of subsidies for the auto industry being proposed, and in response many concerns about these subsidies have been noted. In terms of trade issues, most of these concerns are unlikely to turn into formal complaints. Rather, as noted previously here, they are probably just being put out there to make sure the measures taken are not blatantly discriminatory. For example, a measure like this, which involves a clear GATT Article III:4 violation:
the Consumer and Automotive Recovery (CAR) Act of 2008 ... would provide a $1,500 tax credit to those with incomes less than $250,000 a year if they buy a new car that is substantially manufactured in the United States. (emphasis added)
This is from a Texas Congressman. Here's the bill.