The super structures of Coast Guard and Naval ships are aluminum skinned with steel ribs. Light and easier to maintain.

The hood on my Expy was damaged a couple of years ago by my daughter's basketball hoop. The hood could not be repaired, it required a complete replacement. $1100.00 for the hood alone.

The repairs will kill any savings and will likely force the auto insurance industry to possibly raise rates due to the complexity of repair or the cost of replacing body panels. My personal opinion here.