This is going to be a tough one for me---I own two convertibles.  Driving a convertible with its top down at high speeds could lead to permanent hearing damage.

Researchers from the St. Louis University School of Medicine tested the decibel

levels in the interior of four convertibles at different speeds.

They found that at 55 miles per hour, the noise level was equivalent to a construction site -- and at 75 miles per hour, it was as loud as a jet flying overhead.

While this isn't a big deal for short trips, it could cause permanent hearing damage during long trips.