It is a 25mph residential zone. Cops occasionally use family-type cars. Today I saw a stop involving two siren adorned vehicles: a white four door Ford, Cruze I believe, and a black or charcoal colored Toyota van, newer modeled. Both officers appeared to be in street clothes. They also go after: 1. Rolling thru or not stopping long enough at stop signs. 2. Elmhurst will post new street signs such as "No thru traffic 4-6pm". The a cop will be posted nearby the same day the new sign is erected. When a resident who uses the route on a regular basis, not expecting the posted signage, uses their usual travel route then gets nailed with a ticket. I had a similar scenario a few years ago with new signage deterring thru traffic. I was trying to go into a place of business. The patrol car was blocking the entrance to the place of business, would not move when I waved him out, I was forced to take the foridden route and got nailed with a ticket.