I have never heard of or seen that bar on your generation impala. Maybe on a VFF or fire police POV. We have a ADOT retired member that did refurbish older bars for that generation impala like a LP 6000. Not sure if he had any aerodynamics to use. I don't see a civilian impala powering an aerodynamic bar very well with a power draw like that. Maybe a mini. There is still stuff on sites like galls that should work for the flashers. You could always do what I did, keep your civilian nice and get a dedicated 9C1 to outfit. It has back flashers in taillights already. If I had an aerodynamic, I would temp mount it on one of mine for you to see but I never had that bar in my collection. Yet.