It's more than just the cars. A huge amount of our civilization has something to do with oil. From the plastics, to medicines, stuff for food, clothing. you name it, oil is probably a part of the process somewhere.
Even with vehicals, there's the trucks, trains, ships and palnes that move with oil based fuels. Transporting everything we eat, wear, use and consume.
Our very roads are composed of oil/petroleum products as well. Very little of today's modern world is not touched by oil in some fashion.
I used cars as a base example. It goes beyond just the United States, or even the 'First world'. Developing nations are starting to build up their economies, and much of that is done on the backbone of oil. India, for instance, recently(within the past two years, iirc) began to sell the Tata Nano
. According to Wikipedia:
[The] Tata Nano is a rear-engined, four-passenger city car built by Tata Motors, aimed primarily at the Indian market. It is the cheapest car in the world today. The car has a fuel efficiency of around 26 kilometres per litre (73 mpg-imp; 61 mpg-US) on the highway and around 22 kilometres per litre (62 mpg-imp; 52 mpg-US) in the city.
Sidenote: I would say a true general uses strategy, tactics and logistics. Someone who is an excellent strategist and tactician can and will beat you even if you got the best logistics in the world. If your tactics and strategy suck, you're not going to win.
Not to nitpick, but I didn't come up with the idea. It's an actual quote, from a Russian(Soviet) WWII-era General. He mentioned this, I believe, after observing that the cold Russian winter breaking the German supply lines being the primary reason why the German advance was halted.
As for tactics and strategy defeating pure logistics, I disagree. That very same conflict mentioned just above proved otherwise. The Russians were well supplied and prepared for the winter. The Germans were not, even with their strategically-keen General(s) leading the advance. The Russians ability to hunker down and just plain survive is what pushed the Germans back. They couldn't survive without the logistics.
Move that train of thought forward, still involving the Soviets, but now the Cold War. NATO was massively out manned and outgunned in every possible aspect by JUST the Soviet Union's military. They had more aircraft, more missiles, more soldiers, more rifles.
But due to the poor logistical planning inherent in most centralized planning schemes(Hard-Socialist and Communist governments historically have this problem; see North Korea and Venezuela), they couldn't feed their civilian populace adequately, much less their massive military. The Chinese learned hard lessons from the Soviet failure, and have moved to a pseudo-Capitalist economy. Its central planning will eventually lead it to ruin, provided they do not move away from their top-down management style.
Logistics always has been, and always will be; more important than pure tactics and strategy. It doesn't matter how brilliant a tactic or strategy one has if one does not have the manpower and equipment available to carry out one's plans. Not to mention the very basic necessity of food.