Well the main part of the code is that you get a realtime rendered cubemap. So you have to use a shader that uses both, the texture of the car and the cubemap.

The code works like this:
There is a camera always at the same position as the reflecting object (in this case the car). The camera changes its direction all the time to combine the different angles and renders them on a cubemap.

My code only generates this dynamic cubemap. In the example I used a simple shader from Slins collection. It uses just one cubemap which is rendered on the model.
So in your case you have to use a different shader (Environment Mapping) which also supports texture blending and that uses a cubemap (generated by the code).

I hope you understand

Edit: I think I saw such a shader in one of the AUMs.