My dad worked nights and Mom was a SAHM who also did some freelance stuff from home. They basically had a first come/first served system, and honestly didn't have many conflicts so the second car (usually the one they've had longer) was rarely used. That was perfect when I started driving in high school, because I could usually use that car (even if it was a few years older than I was)

My brother talked them into buying a used Mitsubishi Eclipse back when it was still kinda cool (an '03 model purchased in 2007?). Mom ended up really liking that car and it's not really practical for the handyman stuff my dad does in his retirement, so now they have assigned cars.