1. Gallons needed: 500 miles / 25 MPG = 20 gallons
2. Total cost: 20 gallons * $3.20/gallon = $64
Therefore, based on an assumed MPG of 25, it would cost approximately $\boxed{$64}$ to drive 500 miles. However, this is just an estimate. You should check the fuel efficiency of your specific Dodge Charger model to get a more accurate calculation.