We file Married Separate. Iowa State filing requests us to enter Total Vehicle Registration Fee Paid. Do I put total amount on both, or half amount on both?

For federal return, my wife and I divide the total fees for both cars in half, since we file separately.  I'm a little confused about what to do on state, because it's asking for total fees paid, but I'm not sure if I should continue to divide in half here, or put the full amount for both of us on this question.