The average velocity of an object is calculated by dividing the total displacement by the total time. Displacement is the change in position, and in this case, the car returns to the starting point. So, the total displacement is 0. The total time for the journey is 2 hours + 3 hours = 5 hours.

Given that the displacement is 0, the average velocity will also be 0, regardless of the total time taken. In LaTeX, the average velocity formula can be written as:

\[V_{avg} = \frac{\Delta x}{\Delta t}\]

For this particular case, it will be:

\[V_{avg} = \frac{0}{5} = 0\]