What about one like mine.

Got it from a company called 'Badge it illuminations' who were based in the London area.Sent them the spoiler and they fitted the brake light for £49. Have'nt seen them advertise for a few years now.I don't know if they are still on the go,maybe someone else would know.Only other option is the states for the genuine American spec item.
The wires for mine run through the spoiler holes in the rear window.