access, I had the same Idea with the flashing lights and siren. I have all the parts but have never put it together, maybe I'll work on it next rainy day. here is the 'siren' i bought, works on receiver voltage (I tried it)
http://www.allelectronics.com/make-a...SIREN/-/1.html I have a bunch of flashing leds of red white and blue colors, not quite as good as a circuit that blinks them in a sequence but when I get around to it they'll go on the ambulance body that currently resides on the lunchbox.