Well everyone I just found a hint towards this stuff being 100% true. You know how earlier in the topic there was talk and images about a Blue Cop car's rather then a Black Car's? Well I was needing to check something out on GTA3, so I loaded up my PS2 GTA3 and I noticed something in the introduction movie at the start. When it shows the 2 cop vehicles (a car and a van) there blue. Just like they are in the picture posted earlier. But, on the PC (I have both PS2 and PC versions in case you we're confused) the movie is different, both are actually black. So I'm guessing, yes, the Cop Vehicles we're originally Blue, and when changed, Rockstar forgot to change the movie at the start of the game, they then realized this and changed it for the PC version. Interesting isn't it?
I'll see if I can get some screenshots to prove it to you