So, I made a quick example, as I can't figure out why it's not working, when a quick test positioning a sprite at an offset seems to work.
DEMO GAME
CAPX download
Am using Sin/Cos to convert current angle to an offset like so -
Box.X+(Sin(Box.Angle)*16)
Box.Y-(Cos(Box.Angle)*16)
I can place a sprite at that location on startup and during physics movement and it places perfectly each time, however using the same offset to test collision results in some rather odd behaviour.
It should theoretically be testing for collision against the 16px distance towards the angle the box is facing [ marked by a + ], however it fails to collide, and instead collides when more than 100px away from anything at all.