Having something unique is important to car culture.
In fact with some cars it serves as a fairly significant aspect of it's cost. Where some car won't be particularly special performance wise, but the looks/uniqueness of it is.
For myself this isn't terribly important for a car I drive. Like I wouldn't robe my savings to drive a Roadster 2.0 just to feel unique.
I consciously chose the Model S over a used Ferrari, and I knew back then that Tesla's would be pretty popular.
With the Model 3 there are going to be so many of them that I will want to do something to make it stand out a bit more. I'll probably go the aftermarket body kit route.
Whatever I decide it's going to have to wait till I get my badge, and spoiler. Apparently I won't get those till Nov.
I also think it's important to look at this from the other perspective. When we drive down the road we don't want all the cars to look the same. I fail to see what fun that is. It's important that some cars, and their owners do something truly unique.