[rotorwrench]

It can make contact with cleaning around at least one of the bolt holes on the frame and the corresponding bolt hole on the mount bracket. It's a good idea to use some silicon grease on the bare metal areas to keep it from corroding. This is a common practice for bonding on aircraft structures and it will work on motor vehicles as well. If the bolt & nut hardware is unpainted at contact points, it will carry the bonding through the fastener just fine as long as the hardware is clean and secured properly.