Rearview Mirror Tab
If you drive, chances are you regularly look in your rearview mirror. In case you did not notice, there is a tab at the bottom of the mirror. Apparently, it allows you to change the position of the mirror so that the headlights from behind you will not blind you. It deflects the light but it still allows you to see what is going on behind your car!
Coin Ridges
You might not have noticed this, but both quarters and dimes come with rough edges which are not found in pennies and nickels. Feel free to check the coins you have if you do not really believe us. Anyway, this is from a time when coins were stamped in different weights which reflect their value. They wanted to stop the shaving of coin edges and melting them in order to make new coins. That is why they added ridges using precious metals.