GIMP :: Change Red And Black Car Photo To White Car?

What I am trying to do is change a photo of a bright red abd dark black car to a white car.

In all cases what I seem to be running into is the fact that the programs use the existing colour as the start point and allow only so much variation from that colour (ie about 180 +/- in each primary colour) which does not get me to where |I need to be.

I also tried creating a new layer and filling it with the desired colour then changing the layer from normal to hue. The result ends up being a mix of the original colour and the new colour so for instance if I want a yellow over a blue original colour I end up with some variation of green.