Do you folks not go to a dealership, test drive a car, and buy it?
Over here, it is impossible to purchase a car to come straight from the factory. If you guys can do that, I wouldn't complain too much about a few miles on the odometer.
100 different people could have driven a brand new car before it gets to the person who purchases it.
As for the 100 mile thing, they are demo cars. They are sold as new with new warranty, but are extremely reduced. I bought my wife's car "new" with 900 miles on it. I got full warranty, but it was reduced from $29,500 down to $18,000.
Buying a new car sucks over here. You can't choose exactly what you want as everything today is sold in packages and you can only choose what is on the lot unless the dealer can find something at another dealer and have it delivered (which is driven for delivery.)
Of course, the worst thing is, hardly any are available with a manual, and those that do have the option of manual transmission, it is impossible to find one.
It use to be, before my time, that you could order any option you wanted. Now everything has TC, ABS, power windows/locks, cruise control, remote entry, and AC. Options are usually "Sport package", "touring package", and stuff like that where you have a large selection of options packaged together.
An example is my first brand new car back in 1992. I wanted to make sure I had AC, which wasn't standard equipment back then, but I couldn't get AC without the $1600 audio option. I had $5000 worth of aftermarket audio equipment sitting in the garage waiting to go into the car and I was forced to pay an extra $1600 for a crappy radio and speakers made out of paper so that I could get AC.