The two grills either side of the front Renault badge are looking washed out. I've tried 'bumper shine' and trim restorer but it still looks grey. I don't want them to be gloss black like the paintwork, but I'd like make them darker. Will something like this be appropriate: http://www.screwfix.com/p/plasti-ko..._-Plasti-Kote Plastic Spray Paint Black 400ml ?