This manuscript describes a robot interaction for the driving assistance system of an Ultra-Compact Electric Vehicle (UCEV). Fun-to-drive and safety are important for improving the commercial value of UCEV. To improve fun-to-drive and safety, the improvement of the driving skills is important. However, the driving assistance system of an ordinary vehicle only considers the objective driving evaluation. Therefore, we propose an interactive driving assistance system that considers the relation between the subjective as well as the objective driving evaluation. Furthermore, we install a communicating robot within a UCEV to interact with human beings in real time. As a first step, we propose a driving evaluation system by applying a simplified fuzzy inference, and an interaction timing estimation method by applying a spiking neural network. Through an off-line simulation experiment, we verify the effectiveness of our proposal that is able to generate a robot utterances content as well as estimate reasonable timing.