From the very beginning of the game, you may hijack a Bus,
park at a bus stop, and collect passenger fees for profit.
Now this may seem like a very small amount of money at only $5
per passenger but there are two secrets to this trick.
First, there is NO LIMIT to the amount of passengers that can enter the bus, at a bus stop.
Second, you can park at a bus stop, and leave the game running while you go to sleep at night, waking up with MUCH more money.
The "hidden gotcha" comes with the best location.
Park at the North Point Mall bus stop, facing south towards
one of the purchasable safe houses, 3321 Vice Point, where it
is a known area for cops, security guards, and gang members to
gunfight it out on the streets.
Facing 3321 Vice Point
So at worse case, the bus will get caught in a crossfire situation, explode,
and when you wake up in the morning and check your game, Tommy will be standing
outside the nearest hospital after dying. This has ONLY happened to me one time.
Another "hidden gotcha" is if you get rammed enough times from pedestrian or
cop vehicles, to explode the bus. Those are the only concerns. Otherwise,
this is totally an easy way to make alot of money early on in the game,
when you have low paying missions, and no real way to make big fast easy cash.