First Crime - Hijack vehicle

Hijacking car is simple. All you have to do is walk up to a parked car (or a car going slowly) and
press the corresponding button on your controller set-up that will allow you to boost the car.
Once in the car, be especially mindful of your surroundings. Try not to boost cars around cops so
you don't draw attention to yourself, and be careful of aggressive crime victims who will fight back if their car is stolen. Because of this, you'll want to make a point of getting out of dodge as
soon as any given car is stolen.

GTAIV introduces a complex and in-depth vehicle system, where all vehicles handle differently.
Not only do various makes of car differ from one another, but the amount of damage they take
will also affect how they handle. You can actually stall out cars that take too much damage, and
if they take the ultimate amount of damage, they will be set ablaze. That's your cue to run the
hell away before the car explodes, likely taking you with it to the next world.

As an aside, parked cars are usually easier to steal, but will require some extra effort. Most
parked cars will need to be broken into, which takes time and draws attention to yourself. Cars
stolen like this also need to be hotwired (which requires some simple button-tapping). Also be
weary of stolen cars with alarms, as these will draw even more unneeded attention to yourself,
especially when you're driving around Liberty City with your alarm blaring.