Why? Smallest size, which it maximally beneficial to fitting into tight parking spots, and also, traversing narrow winedy mountain roads.
Then the next question is what is the best color for it? All black, or red?
From a pragmatic perspective, red is superior because it gives you higher visibility. People are less likely to crash in to you because the red is more highly visible.
From an aesthetic perspective, all black is sublime, but the pragmatics of keeping it clean is a huge pain in the ass.
Assuming you prefer a maximally maintenance free lifestyle, black is bad.
