Maps and map coordinates for places mentioned can be looked up on this page.

Fallout 4. Day Tripper Locations:

1. Concord Speakeasy: In the bathroom with the mannequins holding machetes on the second floor (2).
   One is in the sink and the other is under the sink.

2. Concord Tunnels (Civic Access) on a raised platform (1). See below.

3. Goodneighbor: Fred Allen in the hotel will sell them after you get him the special gas.

4. Gunners Plaza, second floor.

5. HalluciGen, Inc.: in a toilet on the second floor

6. Massachesetts State House

7. Oberland Station: southeast in an unmarked trader shack (2).

8. Outpost Zimonja: northwest in an unmarked shack under an overpass (1).

9. Produce Stand north of Vault 81 - one below the cash register, one in the back room.

10. Revere Beach subway station on a desk in an office behind the office with the Protecteron terminal.

11. Saugus Ironworks: lower level inside the smelting pot with a corpse and shopping basket on the floor at the bottom of a staircase (1). It respawns every few days or so.

12. Somerville Place: go north. It's under a ladder next to a statue (1).

13. Warren Theater near The Combat Zone under the concessions stand counter.

14. West Roxbury Stationi: in the back of bottom floor (East) on a bench.

15. Wolfgang at Drumlin Diner randomly sells Day Tripper.

The Day Tripper on the raised platform in the Concord tunnels is on the right near the end of the tunnel. I found it hard to jump up to the platform from the platform below it, even after getting out of my power armor. I finally had to get down into the water at the outer corner of the top platform and face it, get out of the power armor, get back onto the lower platform and jump up on top of the power armor then up to the upper platform.

X-cell Locations:

1. Boston Mayoral Shelter: in a First AId kit inside the bathroom with the skeleton of the mayor.

2. Concord Speakeasy: Upstairs, on the floor beside the bed with a skeleton and mannequin (2).

3. Fens Sewer is north-northwest of Diamond City, through a manhole cover in a main street, in a blue bin (1).

4. Gunners Plaza: in a First Aid kit behind a locked blue door.

5. Harbormaster Hotel: down the elevator on the left, through the "Waterfront" red door, behind the bar on the left (1).

6. Quincy Ruins: 3: one in Mama Murphy's stash on the balcony and two on the overpass.

   You can also buy/trade them from the following locations/merchants, but only rarely:

1. Diamond City, Diamond City Surpolus and Chem-I-Care.

2. Goodneighbor, Daisy's Discounts.

3. Railroad HQ, Doctor Carrington.

4. Diamond City, Diamond City Surplus and Chem-I-Care.