I could see certain accessibility settings of cars such as color blind settings, bold text, even physical personalization ordered for the car based on hereditary or not genetic conditions falling into that category.
Some companies will find that information useful for ads I suppose.
Well
I guess OP said 10,000 / 3,000,000 = 1/300 = .33% so a bit lower but maybe 3 Million is approximate?
Google says 2.048 population so 1/204.8 which is 0.48%