Easiest way to tell for me is the complete lack of chrome trim, replaced by black. Good thing too otherwise I'd never be able to tell it from a 3. It's considerably larger, but deceivingly so. Another brilliant creation from Tesla!Saw the Y on Newport road, Menifee, CA. There is a Supercharger near there, so that could have been the reason.
Could not tell if it was a performance, as it took me a while to even determine it was a Y.
Has family styling somewhere between the X and the 3. Front and rear look more like a sleeker mini X than a larger 3.
It had a good presence on the road. Did not stick out as something weird, but certainly was easily recognized as a Tesla.