Transit Buses, Ambulance Bodies, Fire trucks, Rescue trucks, Air Craft, Military Vehicles are just a few using aluminum bodies for some time. You have had aluminum suspension parts for years on vehicles. Ladders on aerial fire trucks have been using aluminum for years. And they get exposed to weather and heat.
Do some looking and you will find some videos of Ford hitting the beds with golf balls and hockey pucks to show they dent the inside of the beds no worse than the steel beds.
Several cars and trucks not just Ford have been using aluminum for hoods, deck lids, lift gates and doors for a few years. If you look you can even find a video that shows how the new cab can be repaired in pieces if damaged. So by welding, some by rivet's and some by adhesives. The current ultra high strength steel requires special tools and welders to do the proper and safe repairs. Land Rover and Jag have had aluminum bodies for a few years. And guess what at that time they were owned by Ford.
GM and Fiat-Chrysler will all be using more aluminum in there vehicles. Cadillac is already doing it on some vehicles. Just not the cabin area. The Doors, Hoods, lift gates and trunk lids can be.