This paper proposes an analytical model for the packet reception ratio (PRR) of the vehicle-to-everything with non-orthogonal multiple access (NOMA-V2X) with multiple interfering vehicles. The key idea is to reflect the dynamic decoding order of the successive interference cancellation in broadcast networks, characterized in NOMA-V2X, by the locations and numbers of simultaneously transmitting vehicles to an analytical formula. This key idea enables us to spatially analyze the PRR even in any number of transmitting vehicles. Our analytical results showed that NOMA-V2X increased the minimum PRR within a required area around a target vehicle by 0.7 points over the baseline, i.e., V2X with the orthogonal multiple access.