It sure seems like an aftermarket company could capitalize on something like that. It's a lot of space for solar panels and seems like it would be the perfect accessory for an electric truck!
I think the Cyber Truck estimates that its solar bed cover can potentially add up to about 15 miles to the range under perfect conditions. While it's not much, it could cancel out most people's commute or at least put a dent in it as it sits outside their workplace.