Here is one way to move a mattress.
At least it is properly secured, and the “spoiler” in front of it undoubtedly helps a lot.
Almost weekly, I see new-looking mattresses on the side of I-287, after they blew off of the top of a car to which they were not properly secured.
I’ll bet lots of folks have moved mattresses that way. I moved a mattress like that on even w/ my little old Corolla. Wasn’t quite a professionally done, but the mattress made the trip ok. I moved an even bigger item, a home furnace, that way, on top of the Corolla. No freeway driving involved though.
Yea, looks pretty safe. Double-strapped with some beefy ratcheting tie-downs.