Phone, not the wallet
I did some shopping, and put the results in the topbox on my bike.
I used the flat top of the box to rest the phone while I tapped away at Google Maps to find the way to the next store.
Once that was done, I hopped on and was riding away down the expressway at a good rate, when I did the usual patting of the pocket to make sure I had my phone.
Which was empty.
I was in the middle of a major coronary when I realized the phone was now clamped in the holder not 3 feet in front of my face.