Thanks for the compliments!
I used clear cable ties to attach the extra strips and used some semi gloss black spray paint for the grill.
The cable ties wrap around the extra horizontal strips at the centre of the grill by the vertical strip (If that makes any sense
). The grill housing will hold the other end of the strips on. The cable ties are only visible at very close range.
The only problem I've had is that when you pop the hood, the handle tends to push one of the extra strips out of place, but that can be re-adjusted by hand.