The first few years of owning a car are the most expensive due to depreciation. The longer you can defer the purchase, the better. Most cars depreciate to 50% to 60% after the first 5 years. So paying a $1000 or $2000 to avoid paying $30,000 is usually worth it.
see:
http://www.edmunds.com/car-buying/how-fast-does-my-new-car-lose-value-infographic.html
We now buy a new car based on specific need (eg third kid- we needed a minivan) or safety/reliability concerns (eg we are taking long trips to visit family, sports competitions, colleges and absolutely need reliability).
New cars are cheaper now. Internet pricing is much better than haggling with a dealer. And the warranty is much better to have than rolling the dice with a used car. So we are buying new cars and holding onto them as long as possible.