Those that use the Garmin Varia: Do you use it with a Garmin device or your cellphone or both? Does it audibly alert so that if using a phone (android in my case) you can have the phone in a pocket or handlebar bag and still hear an alert - that is, if you don't want to mount phone/garmin on the handlebars? I was hit by a pickup truck from the rear many years ago and while he really dinged up my body, I managed to dent the entire length of the pickup truck bed with my butt!!!!