Does anyone have some advice on how to clean the stock grille?

 

I was wondering about this, too. Next time I wash my car, I'm gonna try using a soft-bristle brush (kind of like the one pictured below). Dip it in the bucket of soapy water and go at it. Then rinse with the hose. I think the bristles will be long enough to reach all the way into all those little 'holes'.

 

Thanks for the advice. I will try that. I had tried a tooth brush, but it was taking too long.