To find the monthly decrease in the car's value, we divide the total decrease in value by the number of months.
The car's value decreases by $4,000 over 12 months, so we calculate:
\[ \text{Monthly decrease} = \frac{-4000}{12} \]
Calculating this gives:
\[ \text{Monthly decrease} = -333.33\overline{3} \]
When rounding to the nearest hundredth, it becomes:
\[ -333.33 \]
Thus, the value decreases by −$333.33 each month.
So the correct response is:
−$333.33 (negative 333.33 dollars).