Measurement of driver\'s state is important in both daily healthcare and prevention of car accidents. Existing measurement methods, however, are too complex and uncomfortable to measure for everyday. A nonintrusive biosignal monitoring system is demanded for increasing the accessibility. In this paper, we proposed a nonintrusive measurement system integrated in a vehicle for recording electrocardiographic (ECG) signals and tested the performance of the system. The system consists of dry electrodes attached to the steering wheel and a wireless communication module using a Bluetooth device. ECG signals measured by our system were compared with those by a conventional system employing wet electrodes during real city road driving. Various parameters used for HRV analysis in time and frequency domain showed no significant differences between the two simultaneously measured ECG signals. The result implies the possibility that developed system could have a potential to monitor health information in a vehicle instead of commercial equipments.