When the car is moving, the pendulum experiences both the gravitational and centripetal acceleration. The effective acceleration is:
\[
a_{\text{eff}} = \sqrt{g^2 + (1.732 g)^2} = 2g
\]
Thus, the time period of the pendulum when the car is moving is:
\[
T_{\text{moving}} = \frac{T}{\sqrt{2}}
\]
Hence, the time period of the pendulum when the car is moving is \( T / \sqrt{2} \).