Old is relative. My car is clearly 'old' as an '06 w/ 220K miles, yet the only repairs required have been a cam position sensor and the expected oil leaks (valve cover gaskets, rear main seal, and a timing cover leak), and 200K worth of maintenance. All stuff I was able to fix myself. So, mechanically, I don't consider it to be old and it doesn't feel old, just slightly aged. However, over the last couple of years, the clearcoat has started to fail on the roof and now the dashboard has cracked. So suddenly it feels like an older car. My 2012 on the other hand, looks and feels brand new, aside from having almost 170K miles on it. I've had to replace a radiator and a starter so far.
I don't like new cars. While I like the power of twin turbo V6 and V8 powerplants, I don't want to have to wear my reading glasses to work the stereo or open the glovebox. I also see more problems with these new cars than with my 'old' cars. I would love to have a choice of new 2000-2010 cars to choose from.
In my mind, I think of cars from the '70s to mid '80s as being old, primarily because they were not desirable to me, although I now appreciate their lush interior and magical suspension that can make Detroit roads smooth. '90s cars are old because they are getting hard to maintain, but they were better than the previous generations. '60s are classic cars. Early 2000s cars might be peak car in my mind, not considering the safety and power advances made since then.