I think it's better to install ETC at the same time.
I had ETC installed at the same time when I bought the car, and I bought Porch at the same time as its Parts.
However, when I look at the wiring coming out of Porch, I think that it is necessary to take out the wiring from Porch before ETCWiring work. If you try to put the Body in the Porch later, the hole for taking out the Wiring will be wasted.
Since the body is fixed to the vehicle body with Magic tape, there is no need to worry about the body going out of control, so even though it is an invisible item, it is doing a good job.
