i want to install a tow bar on my car to put a bicycle rack on. i need a large one that will accommodate 2 adult and 1 child's bike. I have heard this might bend the frame going over bumps. does anyone know either way?

 

Most tow bars on small cars install onto the little tow hood and the you drill 2 bolts into the truck under the spare tire (its how it was on my rsx). Floor of the trunk is strong but not that strong. If you must do this try to put the bikes as close to the back of the car/bumper as possible. Don't see it bending your frame, denting up the bottom of your trunk floor... maybe
.
.
.
.