I have seen this stuff in person. I had the factory rep visit my shop with samples of their wares and I was impressed:thumbsup.
Here s a link to a video showing the durability; you can see half of the differential cover is chrome and the other is gold. The resolution sucks but you can see the reflective qualities of the gold. The poor video quality diminishes the actual tone; but I can assure you it was as gold. Being a candy you control the actual tone by applying more or less concentrate. It would be the ticket for a 3PO; especially with the amount of parts. One word of advice is it should be painted all at once to make sure it matches with the same amount of candy on all the parts so you don't chance a color mismatch where it is not desired.
http://alsacorp.com/products/clear4chrome/cl4ch_video.htm