I will gladly assist. Pertaining to the driving element, to really enhance the caliber of realism, you might consider maintaining two to three car lengths from other motorists, and actually utilizing the parking spaces for parking as well as parallel parking.
Moreover, if a vehicle has entered a four-way intersection before you have, allow that vehicle to proceed first, avoid tailing other vehicles. Maintain a 500 foot distance from a fire engine.
Also, if you would like to emulate New York driving realism, activate your headlights one half-hour after sunset and one half-hour prior to sunrise. This is a driving protocol that is mandated in most states, however. Activate your high-beam headlights at no less than 500 feet from an oncoming vehicle, and at 200 feet when the vehicle is driving in the same direction as you.
You can also adhere to the New York "Right Turn on Red" law, which decrees that in New York City (Brooklyn, Queens, The Bronx, Manhattan), you must make a complete stop at a red light and wait for the change to green before turning. Grand Theft Auto: IV encompasses four of the five New York boroughs, so be sure to stop at all red lights, excluding those in Alderney, which emulates Northern New Jersey.
As a final suggestions, use the crosswalks, particularly in Star Junction, turn your analog stick to the left and right to check both ways before crossing.