I removed my Chrome with Grey grilles, separated the inserts, sanded them with 600 and painted just the inserts with Gloss Black paint, for plastic, and kept the chrome ring.
This is a very easy mod and cost $8.00 vs spending $100 plus on new. You too can sand the chrome rings and paint them also, gloss or matt black, your preference. I like the Chrome/Black contrast look.
2009 BMW Z4 35i/Space Gray Metallic/7 Speed DCT/Premium,Cold Weather & Premium Sound Packages/Nav/Comfort Access/Ash Grain Interior & Dash Kit/AntiTheft/SportWheel/PDC/WindDeflector/Black Kansas Leather/Smoked Reflectors, Side Markers & 3rd Brake Light/Ferrari Red Brake Calipers/Clear Front Mask/Gloss Black Grill Inserts/6000K LED Lighting/De-Badged/Aluminum Pedal Set/Real Carbon Fiber BMW Door Sills/CF Wrapped Engine Compartment Roundels,F Lower Grills & Center Wheel Caps.