Pick on your own size

This morning I dropped off my Honda to get the door replaced and I rented a Hyundai Accent.  I was driving to the daycare and work and there was a car in the left lane that was going well below the speed limit.  I actually had to hit my brakes because I couldn't pass in the right lane.  I laid on the horn and had forgotten that I wasn't in my Honda.  The horn in the Hyundai sounded like the horn on Ava's bicycle.  I felt like I was driving a toy car.   How can you sound intimidating in traffic with a horn that sounds like this?  Who's going to take it seriously??