I don't believe it had a roadrunner, since there would be two holes. All I could find was one screw hole. From pictures it looks like the street sweeper only had one screw point.

I know in 87 chp was using the road runner, since my dads 87 caprice still has it. 89 caprice and 91 crown Vic have them too.

I don't have any info currently on what chp had in 85, but I may come across some. The older wig wag flasher IIRC would have two holes too.

The '92 Motor Transport manual, posted in the CHP resto doc, lists the Streetsweeper. I identified the Unitrol while collecting articles on the '82 CHPs. You can see the Unitrol in two of the articles posted here on the site.