The Final Task
Photographing all 50 Monkey Mosaics will unlock new clothing options for Trevor.
After a couple of days, a Random Event marker will appear on your map near the Los Santos Customs in Burton.
Sneak up on the monkey-masked artist from the west so you don't get spotted, and snap them in the act.
Let them escape, then wait for a text from Space Monkey informing you that a new vehicle has been delivered to the personal garage of the character who photographed the artist.
Congratulations - you have now unlocked the Dinka Go Go Monkey Blista!