The opening is for the toy characters of the show (geo, milli, and bot) to be able to ride in it. One of my unfinished business is to make a divider ("chairs") within that space for them to not jostle all around when played with.
Another thing to do is to add a spacer to back wheels so they don't rub on the body when spinning. I found that to be a problem with the front wheels when I got those situated, so I added spacers for those, but with her birthday being yesterday I had to rush it a little bit for shark car to have come for her birthday (and stayed because he enjoyed it so much! ).
I'll post another photo with them in there when it's decked out all the way. They are the plastic characters that came with another umi zoomi toy. There isn't a "scale"shark car available for purchase so I made this, as is what she asked for.
Looking back, her birthday was baby shark themed, so I should've painted it as a "baby shark car" to mesh the two together. But she did indeed love it!
Thank you for asking. I hope y'all are well, and the best for everyone that has (and hasn't) read this thread!