[Carlos from Spain]

If that grill is chromed (can't tell from the picture) then it will seriously hurt your performance and you will be much better off mounting behind one of the lower black grills.

And even then you will have to experiment first because different plastics can block radar (even if its just plastic), its not only the metal and carbon-fiber.

In some cases its not the plastic itself but rather a transparent covering they have, and when you sand it off the plastic piece no longer will affect the radar (Ex: Seat Leon FR's grill).

And doesn't depend on the make of the car, even within similar models the plastics may vary. For example lets take VW; the plastic of ther grill on a diesel model of a VW MkIII Golf will severly affect the signal, but the GTI version's grill will not at all. Then on the old Passat it won't and on the new one it now does, a lot. Depends, you never know until you experiment yourself, its worthwhile.

So my recomendation is to perform a temporary installation on both places and compare detection range if you are able to (here we use different fixed radars).

You may even try behind the bumper if the others don't work out, some plastic bumpers don't affent the signal much (BMW 5-series for example), and even if its painted, some metallic paints have barely any effect (even if its metallic) but others do.

If I were to bet by looking at your car, my first bet would be the co-pilots side bottom grill, medial to the fog light. Most radars here are on the side of the road so the far passenger's side usually has better "view", also its not chromed, those lower grill plastics "tend2 to be simpler and interfere less with radar. But who knows.

But then again radar here are also facing foward (catch cars from behind) and their signal is 10 times weaker than american radars (so we have to fine tune very well the installation because distances are very short already) so in the states it may not matter as much.