Sunset Overdrive

These are the chests that float down onto roofs sometimes and shoot out green smoke. they will appear on your minimap,after that you just gotta loot them and repeat 24 more times.

By the time I had completed most other achievements and decided to go for this one I already had about 18 already. The best way to get this is to cover ground as quickly as you can.

I found that using the Monorail tracks that go around the city was the quickest, if you fast travel to Traversal Challenge #10 using the challenge log then you will be right below the start of the track just jump on and start riding.

You don't need to do much, just hit your boost every few seconds and let the game do the rest of the work while you watch the mini map. You will see a little icon on the side of the map and when you do just follow it, it will most likely be on a roof and it will be letting out green smoke. Don't worry if you can't find it, it may be still falling from the sky.

Then just jump back on the track and continue on, it only took me about 5 minutes 6 or 7.

I have had a lot of luck getting these to appear when I fast travel to the radio tower which is in little tokyo. Every 2 or 3 times i fast travelled i got one to appear, sometimes two. They were also appearing quite close to the fast travel point so you will spot then on your mini mal if you just traverse around for a while.

Another thing to note is this occured in my game after i had finished the story and i also have collected most of the collectibles apart from graffiting billboards.

Hope this helps guys. Upote if it did :)