1) Create two objects via createVehicle.
2) Attach second object to first object via the command:
secondObject attachTo [firstObject,[0,0,0]]; secondObject setDir 90;
The second object will not rotate 90 degrees off the axis of the first object. Also, if the first object is moving, the second object will lag behind the first object after attaching.
3) Detach the second object from the first object via the command:
detach secondObject;
4) Try to reattach the second object again via the command:
secondObject attachTo [firstObject,[0,0,0]];
Sometimes it works, sometimes it doesn't. When done quickly from an sqf script, often it doesn't work.