My prediction:
(1) 8:45pm, SAU Gold Coast people running late come north up the M1
(2) 8:46pm, Everyone is in the right hand lane, so a mad dash accross 3 lanes to get to the correct exit in time. At this point several of the group will not be able to get accross and will continue north, probably ending up in Logan somewhere. When they hit the roundabout at the bottom of the off ramp, the majority of the group will take the wrong turn to the left. Several will make the wrong turn straight ahead to Yatala Pies, and although the odds are against it, someone may take the correct turn to the right. Doubtful.
(3) 8:52pm, Having realised they are going the wrong way, they will phone a Brisbane SAU member to find directions. The directions will start with "Do a u-turn", after this the Gold Coast members will tune out and do a right hand turn, followed by another right hand turn when the road runs out.
(4) 9:07pm, After negotiating most of the backstreets of Yatala, they will head south for a good 20 minutes or so before realising they have gone the wrong way. I am not sure what happens at this point, but somehow...
(5) 9:48pm, Gold Coast SAU members arrive on the river on a car ferry and are dropped off at distillery rd, as per the Brisbane SAU members instruction. Here they will follow distillery rd, until there is an option to turn. Which they will take.
(6) 10:15pm, Gold Coast people finally arrive and ring Brisbane SAU members to find out where everyone is. By now, Brisbane people are somewhere more than 4 turns away, so the Gold Coast members will call it a night
(7) 10:22pm, Everyone gets flashed by that goddamn speed camera that always sits just past that on ramp.
(8) 10:43pm, Gold Coast sau members whinge about being caught speeding on intarweb forums, followed by organistion of another cruise in 8 different threads for 4 different locations at 3 different times (and days).....