Overlay d3 paths onto Google Maps?

In this example the width and height of the svg are set to 8000 x 8000, which seemed to be OK up to about zoom level 9-10. The top and left are set to -4000 x -4000 to center it. Finally, the projection is shifted/offset so that it draws in the center of the svg:

Enlarge and center the svg:

.SvgOverlay svg {
    position: absolute;
    top: -4000px;
    left: -4000px;
    width: 8000px;
    height: 8000px;        
}

Offset the projection:

return [pixelCoordinates.x + 4000, pixelCoordinates.y + 4000];