I've never used Magical Express airport transportation before, and am considering it because it seems like a good deal. Problem is we will have one more child (17 yr old) with us than is on our reservation. Any chance that we can squeeze an extra person on the bus? How closely do they check tickets, etc. We'll be fine with the baggage, but I don't want to be left with one of us in a taxi. Any thought's I'd appreciate it.