I'm only glad that it is optional, nothing else.
Oh, I think it's cute. I'm not objecting to the fact that they designed a feature that someone else may love - in fact I praise the creativity of it.
But, this feature comes with an insert that you have to deal with when you aren't frunkgating. And given that I have no plans to ever frunkgate with it, it just takes up space for me.
So, idea great! Forcing people to take an accessory at delivery that they'll have to deal with - not so great. (In fact, making it an optional accessory now makes this fun idea a "best of both worlds" kind of thing.)