This. Seriously.
Why do people insist on spending an extra $5000 for leather, power seats, an underpowered "premium" soundsystem, heated seats, etc.? I will never understand this. Those things are anti-features for me. Leather is uncomfortable in the summer, and freezing in the winter. Heated seats make my butt sweat. Soundsystems ten times better sounding than anything Toyota makes are dime a dozen. Brush your mirrors off when you brush your windows, for pit's sake. And learn how to shift a gear, and save some cash now and forever.
The only accessory-type features that I wouldn't to live without in a car either mandatory by law (power steering and brakes, anti-lock brakes and/or traction control, seat belts, air bags, all of which are either currently required in the US or slated to be required in the future) or hard to find cars without anyway, like power windows and locks (I don't care so much about keyless entry, but power locks are necessary in my neighborhood).
Air conditioning is nice but I've lived without it before, and is therefore a neutral feature.