Putting the bikes on the rear of the car is the best option, and the most secure way to do that is with a bike rack that mounts on a trailer hitch receiver like the Thule Epos rack you see here.

and what you should look for when investing in a rack of your own. Best Hitch Bike Rack Overall: Thule T2 Pro XTR ...

The Epos now carries up to three bikes at a time. The Epos can accommodate e-bikes. Thule’s previous hitch-mounted bike rack, the XT Fold, was marketed as being able to handle all types of bikes, up ...