I don't know how many are aware of this, but I just ran across this for the first time. BaT posts completed auction pricing history for the last 4 years, regardless of whether successful or not. On the chart (at the link below) successful auctions (e.g. met reserve) are indicated with black dots, while unsuccessful auctions have grey dots. If you mouse over the dots you can see more information about the car (e.g. auction title, bid price, date). I haven't counted the dots, but it looks like about 40% don't meet reserve.
https://bringatrailer.com/shelby/cobra-replica/