The hearing perturbation affecting the elderly called presbycusis is characterized by the degradation of the perception of high tones and impacts the capacity of drivers in localizing warnings and sirens while driving. We present the results of a user study performed to compare the capacity of traditional and car glass loudspeakers in providing directional alarms inside the car. The experiment compares the number of directional errors and subjective perception of alarms. It was performed in lab, in a real stationary car while the participant was engaged in a driving task on a driving simulator inside the car. Both technologies provide directional sounds with difficulties in perceiving sounds from the back mainly due to the anatomy of the ear as well as the wrap-around shape of the seats. Glass panes performed slightly better than traditional loudspeakers with regard to left/right confusion due to the position next to the ear.