Some quick initial thoughts:

On the docks, could have a boat house, dock, boat, truck.  Fishing equipment etc, plenty of hiding options there.

Junkyard, with stacks of cars.  Could have a crusher, and a magnet lift.

Business district, a main street looking setting with shops on either side.  A few light posts, cars and other items on the streets.

A 50s style gas station, something like this, but with some Lincoln’s or Mercury’s for cover. Maybe one of the cars could have some babies in the back seat as a little Phil Leotardo Easter egg.

A casino interior, with rows of slot machines, a craps table and a place to exchange chips. People running away and an Ace Rothstein style character somewhere looking unimpressed.

Ice cream parlor/bakery: The long countertop with the barstools lined up underneath of it, the window where you can peep the kitchen equipment, several booths lining the walls, a jukebox. 

Back-alley scene: A narrow alleyway with scaffolding up top, a large dumpster on one side with trash spilling out of it, several large bags surrounding the filth, a few rats scurrying away, puddles pooling on the walkway, there's a few lines strung across the alley to hang laundry from, a man passed out with a bottle of liquor in his hand, slumped against the other wall. 

The Boss's Office: A dark office with two desks in them, each with a little lamp on it that shines over a desk filled with papers, several posters on the wall, a pool table, Think: "Tony's office in the back of Bada Bing!"

The scene that comes to my mind is in Godfather when Sonny gets killed at the toll booth. An abandoned toll booth might be cool with traffic barriers and other cars, etc could be used for hiding places. Instead of running the scene could start with you driving like you're the guys killing Sonny.

An outdoor market or flea market could be cool... Daylight would make it extra spicy to have civilians around and maybe you lose points (or lose altogether)  if you get too close to a bystander. There'd be stalls and displays and other store fronts on the side walk, tables.

Outdoor cafe area with a fire hydrant, newspaper dispenser machine, traffic light, cars, etc. Another one where civilians would be a factor.

How about a cemetery? A big one with mausoleums and trees. At night and it's a little foggy, or could be raining. It makes you feel more paranoid and on edge than usual with all the bodies laying around. :)  

I think there should be like a alleyway adjacent to like a theatre district, with like the signage in the background.

I think there should be like an Italian restaurant.  

I think there should be one on a bridge overlooking a city. 

A butcher perhaps, lots of meat and sausage hanging around. Maybe some signs with deals and prices etc

Inside the bar to make an escape out the back door when the sirens get close, a deli where the "old heads" hang out, if you hit one of the old guys instead you're immediately disqualified and have to run away to not get caught for attempted murder of a "law abiding citizen"?

library, cigar shop, city park, mayors office, brothel, baseball stadium?

Inside of a boxing gym.  A RAT could hide behind some heavy bags, pillars, boxing ring, gym equipment like stationary bikes, weights, spectator chairs, a staircase leading to an upper level of the gym

Pictures for Reference

https://mcdn.wallpapersafari.com/medium/69/47/2thgHk.jpg

https://mcdn.wallpapersafari.com/medium/14/5/PuqbpF.jpg

https://mcdn.wallpapersafari.com/medium/38/24/f547hM.jpg

https://mcdn.wallpapersafari.com/medium/98/7/dOBCZa.jpg

Aparment building/the projects/run down vacant houses

A lakehouse - something like this https://c8.alamy.com/comp/D2A5CT/cottage-and-car-circa-1930s-D2A5CT.jpg but with a lake and a boat included somewhere.

Inside of a church. Maybe something like this: https://photos.francisfrith.com/frith/devizes-st-james-s-church-interior-1898_42317.jpg

Outside of a church. Something like this but with more "stuff" https://l450v.alamy.com/450v/p1g05r/exterior-of-african-american-church-c-1900-p1g05r.jpg

A Speakeasy. https://i.insider.com/53f768786bb3f7253729714a?width=600&format=jpeg&auto=webp 

An airport terminal - https://images-cdn.bridgemanimages.com/api/1.0/image/600wm.ETE.15923140.7055475/4129772.jpg

Airport outside - something like this https://cruiselinehistory.com/wp-content/uploads/2015/04/Screen-shot-2015-04-20-at-11.13.29-PM.png

A casino interior - something like https://i2-prod.mirror.co.uk/incoming/article9897618.ece/ALTERNATES/n615/PAY-Fantastic-Photos-of-Nevada-from-between-the-1930s-and-40s-through-an-American-Travelers-Lens.jpg

And I'm all outta ideas. Apologies if any have already been suggested!

Mortuary... either of these looks good and would be relatively empty at night:

https://www.obsidianurbexphotography.com/wp-content/uploads/2017/10/Morgue-S-England-abandoned-mortuary-autopsy-slabs-dissection-tables-side.jpg

https://blog.funeralone.com/wp-content/uploads/2014/12/history-8.png

Used Car Lot:

https://i.ytimg.com/vi/5Ixnc9NeeAU/hqdefault.jpg

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTk5bOej1MDnLo2Qnf4-Vi4WU1_Be5d07goDg&usqp=CAU

Iron Works

https://collections.falkirk.gov.uk/records/images/xlarge/25822/5dd19c69d3f92e2619d073588ac6fb4a3387a662.jpg

https://walessince1945.files.wordpress.com/2018/03/port-talbot-abbey-works-coal-tipplers-conveyors-and-coke-ovens-1954_p139023.jpg