There is only one thing I have used that looks as good as chrome and that's Kosutte Ginsan powder. It needs to be applied over a gloss black (enamel seems to work best). I didn't have anything around in gloss black apart from this old hotwheels truck so I've done the hood to show you how good it is. The glossier the surface the better. I found that it wears off of polished black plastic. It lasts best on enamel, especially if it's applied before it's fully dry. You can easily do complicated shapes by applying it with a cotton bud.
HLJ sell it.
Here's a before and after. This is not quite as good as it gets either as this was just on an old toy car with tired old paint...
