Originally Posted by
flashware
Even if it's part of a larger booking you should still be able to do it as you can do it on a flight by flight basis (unless it's a TA created booking). Jump in and check "Upgrade using Money".
I think MMB "upgrade using money" will only offer POUGs or standard fare difference upgrades - if it works at all which it often doesn't!
For AUPs I think they can only be done at the airport?