I realize this isn't what you asked for, but it's how we deal with keeping our bikes protected. We bought folding bikes. The one on the right is a Giant Expressway, non-motorized. We have two of these. I cobbled together plywood "sleds" which help slide them in and out of the vehicle, a Jeep Grand Cherokee.
The one on the left is an Evelo Dash mid-drive. We now have two of the Evelos. I haven't built anything to help pack them yet, so the picture includes some bungees and padding that I've been using as a temporary measure.
We tow a small travel trailer at times. So, additional to keeping the bikes secure, this arrangement keeps the bikes ready for transport even after we set up the trailer in camp.
Even if this doesn't help you out personally, I figured it might be of interest to someone else who reads the thread.