Howdy and welcome.
Metallic DE are not hard to do at all. However, if you were to ask me, I would go with a darker metallic, like a chain mail or bolt gun that is heavily shaded and then pick out a few details as a highlight. The smaller details will be brighter, in silver or what have you, but the heavy shade, like 3 or 4 washes of devlan mud and badab black, will really help add depth and character to the figures.
My marine army is silver skulls, and they are all metallic with bright silver helmets. I used a blue wash mix to give a different color feel to them separate from the dark metallic bodies.
As for vehicles, again, I would say heavy shading is the key, it adds a lot of visual interest to the figure instead of being a flat metallic color.
Hope this helps.
If you click on my name in the sig, its a link to my blog. I think I have some of my skulls posted there as a reference if you are so inclined.