I've noticed that there's a lot of speculation about the dead end road in Rio, and how part of it is blocked off, thus rendering it inaccessible, or is it? I glitched my way through the road block to find out what lies beyond, and here's how:
There's a glitch/bug in the game that allows you to edit your car when it is in the air/mid jump. Once you exit the vehicle, it keeps moving through the air, and while its doing this, it can go through barriers/walls:
Now to get through the barrier, it took me a very long time. It was hard finding a way to get airborne, and you have to be going at the right speed and hit the barrier at the right angle in order to have a chance of exploiting this bug. Pretty much in short: it takes a ton of luck. But if you keep at it, eventually you'll succeed:
So this is how my car looked right before I entered it and glitched through the gate
See you on the other side...
Success! Now to see what lies beyond...
In short, all there was was an unfinished road. Kinda disappointing but not like I expected much to begin with.
The only other thing I have to note is that people started spawning there: