Starting Vigilante missions in a Tank causes it to glitch into a silver color and glow red and blue instead of its normal green paint job.
Source: Glitches in GTA Advance — CC BY-SA
Mike's clone glitch here, but the real star is that tank going silver with red-and-blue flashers when you boot up Vigilante — goodbye army green!
That crashed UFO at the bottom of the ocean? You already collected its pieces without realizing.
GTA V
GTA Vice City's most famous UFO mystery took 10 years to solve
GTA: Vice City
A GTA ghost you can hear screaming from inside your own bunker
GTA V
Completing one gang mission can permanently break your entire new save file.