It's the '-Z Axis', not the '-2 Axis' which was confusing me! :)
The Z Axis should be the triggers for Xbox pads, where 0 is the default, -1 for right trigger and +1 for left.
So it looks like your right trigger is assumed to be down by default for all 3 pads. What values did you get for the Z Axis in the PadTest when holding down left and right triggers?
I assume that for your wired controllers the Z Axis defaults to zero on the pad test? Is that something you can try?
This might be a hardware/driver issue but I'd like to be sure by making a build which gives more more debug info for you to try. I might be able to work around it. Off to work right now but I'll get this done later.
In the meantime, assuming that the current setup for Pads 1 & 2 work fine in game (as long as you don't try to reconfigure them), you could copy the following over the top of the Pad3 data.
[JOYPAD PORT 3]
TURN_L2 = -3001.25
TURN_R2 = 3001.25
THROTTLE2 = -3003.25
BRAKE2 = 3003.25
SPECIAL2 = 3011
ACTION2 = 3012
THRUST_U2 = 3010.25
THRUST_D2 = -3010.25
REAR_VIEW2 = 3014
CHANGE_CAM2 = 3013
PAUSE2 = 3018
Cheers
Stevie