How to create a ranking system for a racing game.

I'm making a racing game and I've got all other aspects of the race logic working except for the ranking. I'm trying to get player's the position (1st, 2nd, 3rd etc).

My current approach is :

• Place multiple checkpoints on the race track.

• Check whose ahead by using Vector3.Distance

So far this approach works pretty well but the thing is, I can't seem to get it to decrease my rank by 1 when I pass a car and vice versa.

For Example, When I pass a car, I become 1st and when a car passes me I become last. Does anyone know how I can get the ranking system to work flawlessly?

Here's part of the code I'm using to check whose ahead, it's attached to every car :

 for(var i : int = 0; i < cars.Length; i++){
 if(isPlayer){
 
 //If we are a checkpoint ahead, then we become first
 if(checkPoint > cars[i].GetComponent(CarRank).checkPoint){
 rank --;
 }
 
 //If we are on the same checkpoint. Compare our distances and change ranks accordingly
 if(checkPoint == cars[i].GetComponent(CarRank).checkPoint && distanceFromCheckpoint < cars[i].GetComponent(CarRank).distanceFromCheckpoint){
 rank--; 
 }
 else{
 rank ++;
 }
 //If we are a checkpoint behind, then we become last
 if(checkPoint < cars[i].GetComponent(CarRank).checkPoint){
 rank ++;
 }
 }
 }