Some of our customers have found that the built-in protection on the BNC mag-mount is insufficient and can cause damage to their vehicles. It took some time, but we worked with our manufacturer and have developed a custom fit thin rubber sheath to go on the mag-mount to mitigate that issue.
Note that this is not a “cure-all” for magnetic mounts — dust and dirt can still be trapped underneath and lead to scratching! This should protect your vehicle against any damage directly from the magnetic mount, however.
At a future point these will be included on all mag mounts and the price will go up, but for now they need to be added separately. They are quite easy to install as you can see from the photos!