#### Answer

We cannot observe the de Broglie wave associated with the moving car.

#### Work Step by Step

The matter wave or de Broglie wave associated with moving particle is given by
$\lambda= \frac{h}{mv}$
where $h $ is planks constant ,$m$ is mass of particle and $v$ is speed of the particle.
Typically mass of a Car is around 1000 kg .assuming it to be of the order of $10^{3}kg$
Maximum speed of the normal car is 250 km/hr=69.4 m/s assuming it tobe of the order of $10^{2}m/s$
so for normal car putting these value in above equation will give
de Broglie wavelength $\lambda= \frac{6.63\times10^{-34}J-s}{10^{3}kg\times10^{2}m/s}$
$\lambda=6.63\times10^{-39}m$
$\lambda=663\times10^{-28}nm$
which is $10^{28}$ times shorter than the wavelength of RED light. so it is not observable.