Maintainance cost for a new model is lower
Help me understand how. I don't have numbers at work, but I will research at home out of curiosity. My wife bought her 04 Corolla new; my feeling is that she's spent more on maintenance for her car than I have for my last three used cars combined. Mainly, this is a result of factory scheduled maintenance, which I think is only free for Mercedes and BMW.
New vs old is the wrong determinant. Instead, I would consider maintenance costs a function of use
: my wife drives far greater distances (15k mi/yr) than I do (4k mi/yr). She blew through her warranty mileage limits in the first 3 years. Luckily, it's living up to Toyota's reputation - it's been the most reliable car I've ever (co)owned. She's nearing 180k without major issue. I would recommend a Corolla to anyone looking for cheap basic transportation.
Technically all maintenance is elective, though longevity mandates certain maintenance (oil changes, for example). As a car crosses into "beater" class, you still have to change your oil, but you learn to work around other problems instead of repairing them - beaters can be cheaper to maintain.
New cars meet more stringent safety requirements
My 93 Accord SE ($3500) and 97 Integra GSR ($6000) had 4-wheel ABS disc brakes and front driver and passenger airbags. My 01 Accord EX (6000) has all that and side impact beams and side airbags. All this is anecdotal, and anecdotes are not data. You can use government crash-test stats to research safety. But assuming that new cars are safer because standards are more stringent might be erroneous - does DOT retest older vehicles to the new standards? Here again, I think risk and safety are partially a function of use (miles driven, velocity, traffic and terrain, etc.)
Fuel economy has improved in recent years
There's evidence for this. The US BTS says
that average passenger car fuel economy has increased from 28.5 mpg in 2000 to 33.8 mpg in 2011. Frankly, that's pathetic. And I'm not sure if this aggregate data is applicable to you personally. You could buy 34 mpg cars in 2000, just like you can buy 28 mpg cars today. I don't pay attention to EPA numbers except as a ballpark guide. I wouldn't consider a car that couldn't eek out at least 34 mpg, but this is more for my own amusement since I drive so little.
New cars come with a few years warranty
While true, I think this has debatable value. First of all, the warranty doesn't prevent a mechanical failure. They may lessen their expense. "Lessen" because you're still potentially missing work or whatever when something breaks. Personally, I believe warranties serve 2 purposes: to catch any major mechanical flaws early in a product's lifetime, and to entice consumers to purchase new products more frequently. A used car will (or should) have had any/all warranty or recall work done already. It will have "survived" the potential problems of its infancy.
Also, keep in mind that Honda warrants the seatbelt/airbag/SRS system for life (at least, all of mine have had). Toyota does not.
Two great resources for reliability and fuel economy:http://www.truedelta.com/http://fueleconomy.gov/