The Benz is sitting between the Toyota, the Nissan and the Honda. (they are all distinct, clearly separable things so "between seems perfectly correct).
The fact is, whether there are three cars or three thousand other cars, the Benz can only sit between two of them.
Otherwise, it will be among one of the three ( or three thousand) or in front of one, or in back of one, behind one, beside one, next to one, to the right
One example from Practical English Usage (by Michael Swan)
Our house is between the woods, the river and the village.
I suppose the cars can be placed in such an arrangement so the Benz is exactly in the middle of them, in which case it's possible for it to be between the Toyota, the Nisan and the Honda, I think.
I agree that there are situations when it's not a clear-cu