Treehugger Caution: Build guide seem to indicate how to glue on the pairs of tyres, photo of real truck show this to be correct, however it is possible to glue on the inner second tyre the opposite way, removing the spacing, which apparenlty would be wrong. I see photos online of people having glued on the inner tyre, the wrong way facing outwards, which removes the gap between the two tyres and that should be there.