I have a 1980 grand prix and it has silver gauge cluster, and silver ashtray lid, and silver shift plate trim on the center console, and the silver on the console parts are faded..it looks like the silver pattern is going from side to side..how do fix the faded silver on them parts ? I can't figure out how pontiac did that back in the 1980s .it looks like a Brite silver. Any help would be greatly appreciated..

Post some pic's of what your workin on.  

You can have all the plastic rechromed, but I'm sure that would be more expensive than finding new/used parts. Check out the OPGI site.

https://www.opgi.com/grand-prix/1980

Those type of parts are vacuum deposition plated! Redoing them would not be easy or cheap, if you could even find it. Best bet is either what JustA said or find a good 3M dealer who knows their stuff. 3M sells all kinds of pinstripe (contact) tape & they sell it in all kinds of colors including chrome, silver & many variation of those. They come in all kinds of widths! Anywhere from a 1/32 wide to 2 feet, depending on the color. If you know how to use an exacto knife, you should be good to go.

The case of LAST resort would be to try to repaint these parts with some sort of "chrome" paint. This will require careful sanding and taping the plastic to gain mechanical adhesion but not aggressive enough to put deep scratches into the plastic. My personal experience with chrome paints show they aren't particularly durable to parts that involve commonly touched parts. So I'd be wary of long term durability for your console parts.

I support JUSTA and Last Indian recommendations. Find either new or good used parts would be my first choice. 3M tape second, and paint dead last.

you could consider getting the parts Hydrodiped ! i did this with some parts and had them done in carbon fibre look, came out great !

That's an interesting idea Kiwi. I had not thought of that.