hello nathan here. I'm still only a REAL noob at this scripting stuff and need things explained to me.

i don't know how to make my mesh collider (for my tank) to translate backwards on the Z axis?

heres my code:

var speed = 5.0 ;
var rotationSpeed = 5.0;

function Update () 
{
   transform.Rotate(0, Input.GetAxis("Horizontal") * rotationSpeed,0);

   if(Input.GetAxis("Vertical") )
   {
      transform.Translate(0,0,0.2);
   }
}

i haven't linked my speed variable to my script yet. but my problem is, How do i make my tank go backwards? when i push forwards it goes forwards, and when i push back it goes forwards?

any help is truly appreciated. I'm also taking a look at the racing can tutorial.