The world needs a new source of energy, an unspillable source.

Gas / Electric hybrid – electrical accessories?

If i were to give a hybrid vehicle to a teenager, and they decided to add a bunch of high powered electrical equipment:

1. Does this utilize the same battery that the car motors use to propel the car.
2. Do gas-electric hybrids have alternators capable of generating electricity while the car is running?
3. What are the limitations of adding additional electrical accessories to the car? ie. DVD players, video screens, amplifiers, extra power outlets for laptops