It depends for whom and in what run. In the short run, it is probably good for us, because we can benefit from cheap overseas labour. It is probably not so good for the consumers in the countries where the stuff is produced, because they cannot compete with our buying power. When it comes to food stuff, that can be a difference between life and death form starvation.
In the long run, however, it is probably good for everyone in the producing countries, because it produces long term economic development. And in the long run, how long do you think 6 or so billion producers of the world will tolerate the parasitic behavior of 300 million of US consumers?
The way I would argue this is not that cars is altogether good or altogether bad, but that it is good in one context but bad in another. Many European use cars as a supplement of mass transit and that is basically a good thing, because people can make a choice between modes of transportation that best suits their needs in any particular situation. In the US, however, most of the population has not choice - they have to use cars because the industry and its government lackeys have so decided - albeit most US-esrs are too stupid to see that choices have been taken away from them in exchange for a social status symbol.
The way I see is that there is no way that you can rationally discuss the wastefulness of the US way of life - not just the use of cars but overall consumption - because most people would staunchly defend their wasteful consumption patterns as "their" way of life. The only way to change is to reduce the spending power and thus force the population to make more efficient consumption choices. Before that happens, the Hartfields and Co. will have their field day with their love of conspicuous consumption that benefits, inter alia, the working class.
Wojtek