Render a Quad model on top of a Texture image

Question

I am trying to create an Augmented Reality application for vehicle tracking. In the application I want to place a quad model to track the vehicle. For this purpose I draw a quad at a particular screen coordinate every time the texture is updated. The problem is, I am not able to place the quad model at the exact position on the texture.

Below image shows what exactly I want

As in the above image a green quad needs to be placed exactly at the behind of the vehicle.

I have done it in the following ways,

Viewport size ( 0, 0, 1280, 720 )

1. Render a Texture

• Created a Texture of size 1280x720 and rendered with default modelViewProjection (Identical matrix)

   GLfloat vVertices[] = { -1.f,  1.f, 0.0f,  // Position 0
                               0.0f,  0.0f,        // TexCoord 0 
                           -1.f, -1.f, 0.0f,  // Position 1
                               0.0f,  1.0f,        // TexCoord 1
                               1.f, -1.f, 0.0f,  // Position 2
                               1.0f,  1.0f,        // TexCoord 2
                               1.f,  1.f, 0.0f,  // Position 3
                               1.0f,  0.0f         // TexCoord 3
                           };
   GLushort indices[] = { 0, 1, 2, 0, 2, 3 };```
  
  
  

2. Drawing a Quad in 3D world

   • I have used the following model view projection

   m_unWidth= 1280
   m_unHeight = 720
   float    aspect = (float) m_unWidth / (float) m_unHeight;
   Mperspective = glm::mat4( 1.0f );
   Mperspective = glm::perspective( glm::radians(45.0f), aspect, 0.1f, 100.0f );
   Mview = glm::mat4(1.0f);
   Mview = glm::translate( Mview, glm::vec3(0.0f, 0.0f, -2.0f));
   glm::mat4 Mmodel = glm::mat4(1.0f);
   Mmodel = glm::translate( Mmodel, glm::vec3( POSITION.X, POSITION.Y, 0.0 ));
   Mmodel = glm::rotate( Mmodel, glm::radians(-80.0f), glm::vec3( 1.0f, 0.0f, 0.0f ));
   
   

I have used coordinate conversion function to map into [-1,1].

NDCPoint ACCOverlay::ConvertToNDC( unsigned int unX_i, unsigned int unY_i ) {
const int width = m_unWidth;
const int height = m_unHeight;
float x = float(unX_i) * 2 / float(width) - 1;
float y = 1 - float(unY_i) * 2 / float(height);
NDCPoint point;
point.x = x;
point.y = y;
point.z = 1.0f;
return point;

}

Could you please explain how to map quad model at the correct place of texture in perspective projection.