I wasn't thinking of Martha and Jonathan, but if your are, go with it.
I was simply thinking in terms of letting people believe what seems more reasonable.
In a never finished Fic I have Clark, who is not then superman flying a pilot to a plane when hijackers have killed the pilots. Lois Lane and some others have taken back the plane but can't land it.
Clark garbbed in a head covering helmet,and a flightsuit with what appears to be a huge backpack with some odd metal tubes flies the pilot, a reserve Air Force pilot who flies commercial passenger jets, to the hijacked jet in flight. The reservist believes the backpack to be classified gear that allows them to fly.
Likewise if someone sees Clark using his heat vision while holding up a hand with a glowing Goa'uld Ribbon Device, at the object he is using heat vision on, well most people would think it was the tech, not a guy shooting beams out of his eyes. And if his eyes turn flame red, well in Stargate a Goa'uld's eyes often turn flame red.
Or if Clark is wearing a box on his belt that clauses a glowing aura around his body and someone sees bullets bounce off, most people would focus on the box, not assume the human looking man was an invulnerable alien.
Going back to the ultralight aircraft. Having one and being seen to arrive using one and passing through customs even if he really flew on his own would create a believable paper trail. Which would most people believe that someone kept poor records or that a man could fly on his own?
"Man Of Steel" raised the question; "Is the world ready to accept a super-powered alien?" Assuming a Clark who does not think they are ready, who is hiding, as Clark did before meeting Lois in Metropolis, as the MofS Clark did until being outed on TV, camouflage makes sense.