Older Chevy equinox 2010-2017 model, unmarked. Usually police SUVs in my area are Ford Explorer or Dodge Durango so it caught me off guard.

I heard sirens approaching but didn’t see where they were coming from (i was also checking in rear view) - I slowed down but failed to pull over because I was looking for the lights

I was confused after this

Could it have been an undercover officer who forgot to turn the lights on - or could it have been a civilian impersonating an emergency vehicle?

Thoughts?