for reflections , Lux glass 2,. Lux Metal 2, or Glossy coating, will automatically have reflections,. you can also create a Lux Mix (two options) and have a base material mixed with a reflective,. or,.. Car paint,. will also give you multiple layer options,.
...or simply the glossy material will give you some level of reflection with higher specular levels. Set roughness to zero and you will get smooth reflections, increase it a bit to get blurry reflections.
I think Shiny Metal is basically the Metal shader with a glossy coat, which you can get using the Lux Mix material. You can get reflective silver / chrome metals with just the Metal material.
I suggest setting up a very simple scene and having a play with materials and their various parameters, just to get the feel of them. Some behave differently than their Carrara counterparts. There is some comprehensive documentation on the Luxrender Wiki site, but keep in mind that sometimes materials are missing some parameters in their Luxus implementations.