What I do (I also have a honeycomb grille), is LIBERALLY dress the plastic with good 'ol Armour All...
More specifically, before I wash or detail my car, I just CAKE the area with spray, and make sure I have covered all areas using a old paint brush...
Then I LEAVE it on there for maybe an hour (in the shade)...
Then lightly wipe the plastic with a cloth (and any overspray on the paint), then proceed to wash/detail the car...this way, you don't end up with that unnatural, super-shiny plasticy look...
I prefer this method because a) it's easier, and the results are usually better
and b) after washing the whole car, I don't have to worry about getting any plastic protectant on the cars finish (maybe it's just me, but I can NEVER get that stuff on perfectly without overspray and/or wipe marks on the paint)