Just make sure the invisibility booster isn't faulty...

Dear Harry,

Avoid planes.  Stick with flying cars.

Love,
Ritchie Valens, The Big Bopper, Buddy Holly, Lynyrd Skynyrd, Patsy Cline, John Denver, Otis Redding, Wilson the Volleyball, snakes, The Passengers of Oceanic Flight 815, et al.