But the object doesn’t enter at speed here it’s stationary. If a hoop is thrown at an object and passes around the object the object is still stationary. The speed of the portal relative to the object does not impart movement on the object.
The quicker the portal moves the quicker the object appears on the other side but for the object to shoot out it means energy is being transfered from the car to the object.
If you’re right then what happens If the two portals are moving at equal and opposite speeds?