Does anyone have any good ideas about how to deal with these spots on the silver trim around the rear plate? I've tried a detail spray with no luck. I didn't want to use a rubbing or polishing compound because I'm afraid I'd rub through the silver.

Edited to add: 2011 RDX SH-AWD

 

On my 09 silver RDX, that area really is painted. But, is that really paint on your vehicle? if yes, then why not use the same wax as you use on all of the other painted panels of your car? so I am guessing that part is really a molded PLASTIC part - which is probably why you used a detail spray.

I would not use either rubbing or polishing compound, nor a cleaner wax - these would likely scratch the smooth plastic finish. And again, I am guessing that the part is NOT actually painted.

I recommend Meguiar's M21 fully synthetic paint sealant, aka, wax-for-paint, the same stuff I use on my RDX body paint, as well as all smooth plastic parts, either silver or black.

The 07-09 RDX models have a similar problem with water spots, hard to remove, on the silver surround on the front around the turbo intake, and on the leading edge of the hood. M21 will remove any water spots, discoloration, bugs, etc. with some gentle rubbing - allow to dry then buff off. Will also help to prevent more spots, esp from acid rain, etc.

You may be able to find M21 at NAPA, but more likely, you will need to visit a body paint shop: about $25 or less for 16oz. liquid bottle.

LINK: BLACK PLASTIC trim maintenance
https://acurazine.com/forums/showthread.php?p=15078978#post15078978

 

I'm no detailing expert, but I'd try a cleaner wax with gentle pressure. I've got a tub of mothers carnauba cleaner wax kickin around for stubborn stuff like that since I generally use Collinite 845 on my paint, which doesn't do much cleaning.