I think it's a mistake not to sell stuff like apparel - I would have bought something had it been there. Ironically, I took a stroll by the Mercedes store in Markville after dropping off my S to get the windows tinted and thought it helps to draw people in. I know BMW does it in their store (to the point of excess). Perhaps they'll reconsider this position once the enthusiasm dies down a bit.
Heck, imagine if they got a slew of toy model Teslas - they'd fly off the shelves (even the Hotwheels ones).