Did the car come from the factory with them painted silver? If so and you decide to go red, purchase another pair and have those painted, just in case you wanted to put the car back in original factory condition. I like the silver myself.
Yes, the 2009's have these silver vents.
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2009 Porsche Boxster - Guards Red/Tan
Speed has never killed anyone, suddenly becoming stationary… that’s what gets you. – Jeremy Clarkson
I like the red or black option better than the silver. Have you considered painting your brake calipers at the same time? Red calipers would give you a triple red effect and it might add another layer of cool! Just a thought.........