The shifter in my 5speed manual OZ Rally tends to get sticky as the car warms up. It doesn't spring back to the middle (3-4 position) when in neutral like it should; I have to push it from side to side and guess where 3rd is which is quite a problem when driving. There is also a rattle when its in neutral and the clutch is not pushed in (like when sitting in a drive thru). I don't know if that has anything to do with it or not, but if anyone knows what could be wrong and what I could do to fix it that would be great!

 

Most likely the bushings under the hood.
The bushing could be either torn, or the inner metal sleeve could be seized on the pivot pin.
Mines were seized and torned. I replaced mines with rollerskate bearings as advised by someone here, and it's been great ever since.