You have the right to choose your repair shop. Your insurance company can not require you to go to a particular repair facility.

Most of the dings and chips in a car's exterior paint can be covered my most laquer or enamel nail polishes

There is no legal requirement that you obtain more than one estimate for your vehicle repairs.

Unibody cars require more re-enforcement than Rigid-Chassis Vehicles

Unibody cars require more re-enforcement than Rigid-Chassis Vehicles