I would be careful putting large objects in front, it greatly hinders the airflow into the radiator.
There are waterproof covers for bikes when traveling to help in keeping them clean, just make sure they are tightly wrapped around the bike to keep from getting torn.
Ebikes are very heavy compared to others, upwards to 65lbs. Something to think about when traveling.
This trip was our first time out with two ebikes. I first mounted on the Jeep along with the watercraft trailer. Man was that to heavy for the Jeep. After some thought I mounted them between the truck and Jeep. I used a GEN-Y GH-404 offset dual receiver hitch along with a 6in raise for the Jeep tow bar and a 4in raise for the 1up super duty bike rack. I can still get into the camper using the Fox landing.
