Don't crow too loudly, GM recently donated a bunch of new Suburbans to the Nature Conservancy.
ALL big companies do things for all kinds of organizations. Its called advertising. If loaning a few vehicles out generates 1% more good will or 1% more in sales, it is a cost-justified business expense.
To not do business w/ a company strictly over that type of would force you to NEVER buy anything from anyone.
GM is the only American car maker that comes close to "American" built.