I've owned many Demo cars from various manufacturers, some with low (under 200 miles) even one with 9,000 miles.
one (of several) of the things to verify when buying is the warranty.
for example with GM cars, if the vehicle was never titled with the DMV, and carried dealer, manufacturer, or state issued dealer DEMO plates (special event plates for golf, super bowl, etc.) then the original warranty goes into full effect with the first owner that titles the car, with my 2010 Avalanche for example, that truck had 9,000+ miles on it, but only wore dealer plates, so my warranty started at 9,000 miles so it was a 3/36 that actually expired 3 years the from the day I titled it or 36,000 miles from that day (so 45,000 on the odometer). BTW I got over $20K of MSRP on that truck. Paid $43K OTD then traded it back in on a 2012 Camaro, drove it 2.5 years, and got $38K on the trade.
same with my Lexus RCF, I bought the car with
however, some manufacturers and I have read hear Hyundai/Genesis is one of them, start the warranty the day the vehicle goes into service regardless if that is as a demo or titled vehicle and if you purchase it, you are technically the second owner, and while the original 5/60K warranty will still be in effect, the 10/100 powertrain does not transfer to the second owner.