I did do this simpel animation to show some people how the swedish police stops cars :) it is done in paint net,
step 1 the police presses the horn and turn on the "stop light" which alternates between red and blue.
step 2 the red light stops to flash only the blue one does,
step 3 (if the car not all ready has stoped, if stoped go top stop 4) the rest of the flash lights starts + the siren
step 4 when the car has stoped the "stoplight" stops and only the "blue lights" are on, the siren is off (step 4 is not in this video)
(http://www.youtube.com/watch?v=1iadHXCBmEc)
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this video has step 4
(http://www.youtube.com/watch?v=8B_uFnbaxyc)
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