This paper focuses on the performance analysis of a camera-based vehicle-to-vehicle visible light communication system employing undersampled phase shift on-off keying modulation under interference scenario. Two Nissan Qashqai front lights with daylight running light emitting diodes based lamps are used for communications. The bit error rate (BER) performance of the proposed system is experimentally measured for a transmission span up to 24m focusing mostly on the side interference due to reflections. Based on experimental data we demonstrate reduction of the system performance due to the side reflection and illumination of the detector by other light sources which have to be taken into account during further data processing. We provide with further statistics for particular shutter speed and transmitter power setting and discuss BER improvement especially to meet FEC via the method of the adaptive region of interest.