This paper present the investigation on the dynamic analysis of cars with uncertain parameter under random road input excitations using a quarter-car model. The sprung mass, unsprung mass, suspension damping, suspension and tyre stiffness are considered as random variables. The road irregularity is considered a Gaussian random process and modeled by means of a simple exponential power spectral density. The mean value, standard deviation and variation coefficient of the vehicle’s natural frequencies and mode shapes are obtained by using the Monte-Carlo simulation method. The computational expressions for the numerical characteristics of the mean square value of vehicle’s random response in the frequency domain are developed by means of the random variable’s functional moment method. The effects of the randomness of the vehicle’s parameters on the vehicle’s dynamic response are investigated. The method proposed in this paper can be further developed for sensitivity analysis and dynamically optimal design of vehicle parameters.