Projector affected by light and shadows(car vinyls, blood spatter or bullet holes)

I’m trying to project a decal onto a car that is affected by light and shadows.

I’ve messed around with this for many days now, here’s what I have:

    Shader "VinylShader"
  Properties {
  	  _Color ("Main Color", Color) = (1,1,1,1)   	
     _ShadowTex ("Cookie", 2D) = "" { TexGen ObjectLinear }
     _FalloffTex ("FallOff", 2D) = "" { TexGen ObjectLinear }

  Subshader {
     Pass {
        ZWrite off
        AlphaTest Greater 0
        Offset -1, -1
        //Fog { Color (0, 0, 0) }
        Color [_Color]
        ColorMask RGB
            Material {
                Diffuse [_Color]
                Ambient [_Color]
            Lighting On
            SeparateSpecular On
         Blend SrcAlpha OneMinusSrcAlpha   
        //Blend DstColor One
        SetTexture [_ShadowTex] { combine texture* primary // primary, ONE - texture
           Matrix [_Projector]
        SetTexture [_FalloffTex] {
           constantColor (0,0,0,0)
           combine previous lerp (texture) constant
           Matrix [_ProjectorClip]

Those who want a simple decal system, download the boot camp demo and look at the decal system there. Might not be the best choice, but it’s free and it works great if you tweak it a bit like I did.