You know, this is a profound question... I love this kind of food for thought! Thanks for asking.
First off....
Uh oh, here comes my idealist personality. Ready? Here goes nothing:
If there were no cars, there'd be (pros, then cons) less depression. More time in the sun. More exercise. Fitter people. That is, assuming we didn't revert to horses. Even then, the wind blows in your hair... You can say howdy to fellow riders instead of being encapsulated within a glass bubble with a stereo blaring inside. We'd have less people whining like kindergarteners about people almost accidentally bumping into them. Slower-paced, more patient society. We'd have better hearing, going back to that stereo blasting comment. We'd be exposed to weather more often, feel the icy chill of winter against our faces, and the glaring heat of summer-- and why that's good, I don't know, but I just know it'd give us more character. More definition to our spiritual and emotional muscles.
Then, for the cons? Longer time getting to the hospitals and grocery stores. More hours between us and our loved ones. Yeah, sometimes we really need cars-- when I had a ball of earwax growing so large it was about to rip my ear drum apart, we got to zoom down to the ER and get it blasted out. (I was 16, and it had me screaming and crying like a 5 year old child.) So cars are good... Not to mention, cars are incredibly interesting if you learn about them. Really fun machines to study.
But shoot, look how much we're spending on gas every year. For me: 20 miles driven a day, 7 days a week, so that's 140 miles a week. Takes about 2 and a half weeks to burn all the gas in my car. So I fill up once every 2.5 weeks; 52/2.5 is about 21. 21 x's the amount I spend filling up each time is about $34 x's 21... is $710 a year, which actually for me winds up being about $1,000 with all the times I go across the state to see my family, and the non-school driving I do when doing stuff with friends. $1,000... Provided I didn't need a vehicle for any kind of immediate emergency, I spent $1,000 on being impatient, unfit/unhealthy, and comfortable.
I think oil has a bigger impact on our society, but not for the better. No, I'm both right and wrong, because American industrialization desperately needed oil for the energy to reach the heights it's attained. But I'm personally fine being, except for hospital technology and my hearing aids and the abundance of food (but industry's preservatives don't help any), on the level of "less fortunate" countries, who I believe may be better off than Americans in terms of mental well-being.
Sometimes I think that, with all our racially embittering exploitation of others, with all our sluggardizing technological achievements, and with our predominantly and unjustifiably hierarchical history virulently weaving its way into our present society's bloodstream, we white people make a pretty good mess.
I still have a lot to say, but I'm going to stop right there. Because I'll go all night long.
And Luke: very true