The following videos show the exhaust problem with the 2018 Odyssey.
The problem is reproducible by starting the car in the morning after sitting all night and driving it about 50 to 100 feet.
As the 7/15 video shows, if the car is just started and not driven, there is much less visible exhaust. The Honda inspection occurred on 7/12. The inspection report does not say that the car was moved 50 to 100 feet immediately after starting.
6/14
https://www.youtube.com/watch? v=is1JelzEUA8
6/15
https://www.youtube.com/watch? v=CO9qt1qu6GY
6/23 morning
https://www.youtube.com/watch? v=d7-__eWxu9U
6/23 evening
https://www.youtube.com/watch? v=98Yq4r8illw
7/11 morning after driving 100 ft and after about 5 min
7/13 morning after inspection crv compare 3 short video 6
7/14 morning no garage crv compare 1 short
7/15 morning no garage did not move less smoke
7/16 morning back out of garage 50 ft drive forward 50 ft lots of smoke