The LEDs look cool. The ad on eBay is an abomination to the English language though.

I agree that I wouldn't do it though unless you were changing ALL of the LEDs to a new color - AC, radio, gauges. It might not be too expensive but may be a major PITA.
I think the spoiler stickers are meant to look cool when the car is parked and someone puts their spoiler up manually. The spoiler only comes up at 75 mph and you don't want anybody close enough to read the sticker at that speed any way... I agree that the angle is all wrong too. If I was going to do a sticker like that, I think I'd get one that reads, "Bye, Bye!".