Quote Originally Posted by mklotz View Post
This gives me concern.

My Honda Accord sedan has a paddle switch on the under side of the trunk handle. If the remote is in the car or nearby, pressing this switch unlocks the trunk.

It's not inconceivable that a horizontally rotating brush like the one in the video could tap that switch. Fortunately, I don't go to that type of car wash but it's still something to keep in mind.
Leaving the vehicle in gear should prevent the tailgate from opening. At least that's how it works on my wife's Explorer - has to be in Park.