If the pull is done horizontally, then the net force on the car is
∑ F = T - f = (1500 kg) (3 m/s²)
where T is the magnitude of the tension in the towing cable, and f is the friction which points in the opposite direction. Then
T = f + (1500 kg) (3 m/s²)
T = 2500 N + 4500 N
T = 7000 N