I did a similar setup with an IPod Touch only I used the hook side of the velcro on the back of the rubber case on the Touch and stuck it to the velcro that holds my windshield bag lid closed. Bad idea! Driving through a bridge construction site in the middle of a 33-bike ride the velcro let loose that I had stuck on the ipod case. (NOTE TO SELF: Never stick velcro to a rubber ipod case!) The plug pulled out of the Ipod. My stereo automatically switched back to the FM radio which somehow had been cranked up to max volume. I thought my helmet was going to come off my head! I didn't realize what had happened at first. I felt something brush my leg but immediately switched my attention to my nearly ruptured eardrums. The ipod bounced along the pavement and seeing that there were about 25 bikes following me through this construction zone, I figured I had just destroyed the Ipod...so I just kept riding. A few of the riders behind me during thr ride said they saw something come off my bike and bounce and tumble down the highway.
On the way back home, I decided to stop and walk alongside the barriers on the bridge and "pick up the pieces" of the Ipod as I was sure it probably had been squished numerous times. Imagine my surprise when I found it, laying scren-side down alongside the barrier, about 4" from the path of the traffic's tire tracks STILL PLAYING THE PLAYLIST I HAD BEEN LISTENING TO WHEN IT FELL OFF.
If anyone owns an IPod Touch or a IPhone, I highly recommend you get a rubber case made by InCase. There wasn't a scratch on the IPod and only a very slight scuff on the rubber case. Just don't try to attach it to your bike with a piece of peel-and-stick velcro!