This is how you do it in javascript-

var obj1 : Transform; //this is you
var obj2 : Transform; // this is object2
var transformDist = 30;// this is the distance

function Update(){

if((distance >= Vector3.Distance(obj2.position, transform.position)) && (GetButtonDown("e")))
     transform();
}

function transform(){

Destroy(gameObject); //destroys your player
var replace = Instantiate(obj2, transform.position, transform.rotation); //this instantiates object 2 
}

//drag your player on the obj 1 slot and the car to obj2 slot 
//P.S. I haven't tested this script