The Dash should be a little difficult to insert into the mount on the first try, and settle in from assembly after a ride or two, then it should be relatively easy to install yet still fit snugly with minimal vibration. Here are 2 videos to help show the correct and incorrect way to use the mount:

Dont be afraid to push down the first time, and make sure to first install the mount on your bike, that makes using the mount much easier!