Hi,
Have the same problem with transport to the Brisbane Terminal. Good news, Andrews Parking Nundah are offering a shuttle to the Cruise Terminal and the booking may be done online. The options are Cruise in/out Brisbane, Cruise out Fly in, and Fly in Cruise out. For a 2 week car stay, drop off at the Cruise terminal and pick up at Bne Airport, cost $180. Apart from the cost, only other disadvantage is that you cannot nominate the time you would like the Ship shuttle. Andrews will advise the shuttle times 48 hrs from sail date.