Women also tend to earn less money, being dependent on their husband's income for much of their working-life. The SSA has actually studied this issue, and women tend to be much more likely to exhaust all other forms of retirement savings and subsist exclusively on Social Security benefits: http://www.ssa.gov/history/reports/women.html

Your car insurance would cost more if you were a woman? Citation needed.

My impression is that most car insurance costs more for a man, because men tend to be more aggressive behind the wheel, and that translates into a higher incidence of accidents. At least, that's certainly the case for young drivers.

I attempted to prove it with a quick quote from Progressive, but they want a real name so they can check credit history, and I wasn't willing to give it to them. So I can't (easily and quickly) prove that you're wrong, but I'd like to hear why you think you're right.