Sure, GTA: San Andreas might've had a bigger environment to explore than Grand Theft Auto IV.
But you've never seen a more densely-populated, detailed and engaging environment in any other video game, ever.
Board a vehicle with the selected weapon and input any weapon cheat again (refills ammo).
The weapon you selected will now be usable for drive-by mode.
With another car or by just walking, push Ceasar's red car up the pier and over the edge of the sidewalk into your nearby safe house garage to the left. Not only is it a pimp red car, it's also BULLET PROOF, which helps alot this early in the game.