“Buckle up! It makes it harder for the aliens to suck you out of your car” is a jocular saying that has been printed on many images.
   
“‘Buckle Up: It Makes It Harder For Aliens To Suck You Out Of Your Car’ -bumper sticker wisdom” was posted on the newsgroup misc.writing on June 22, 1999. “Buckle up. It makes it harder for the aliens to suck you out of your car” was posted on the newsgroup tx.religion.pagan on September 29, 1999. “Bumpersnicker on a white Jeep: ‘BUCKLE UP: It makes it harder for the aliens to suck you out of your car’” was printed in the Spokesman Review (Spokane, WA) on October 29, 2001.
 
   
Wikipedia: Alien abduction
Alien abduction (also called abduction phenomenon, alien abduction syndrome, or UFO abduction) refers to the phenomenon of people reporting what they believe to be the real experience of being kidnapped by extraterrestrial beings and subjected to physical and psychological experimentation.
       
Google Groups: misc.writing
Election 2000: The Millenial High Colonic
HellPope Huey
Jun 22, 1999, 3:00:00 AM
(...)
HellPope Huey
“Buckle Up: It Makes It Harder For Aliens
To Suck You Out Of Your Car” -bumper sticker wisdom
     
Google Groups: tx.religion.pagan
Pagans hit Texas Monthy Magazine!
MarilynDln
Sep 29, 1999, 3:00:00 AM
(...)
Blessings,
Marilyn
Buckle up. It makes it harder for the aliens to suck you out of your car.
 
29 October 2001, Spokesman Review (Spokane, WA), D. F. Oliveria column, pg. A6:
Bumpersnicker on a white Jeep: “BUCKLE UP: It makes it harder for the aliens to suck you out of your car.”
 
Twitter
Valued Sony Customer
@VSC
Best bumper sticker of the morning commute: Buckle up: it makes it harder for the aliens to suck you out of your car.
10:51 AM · Jan 24, 2008·Twitter SMS
   
Twitter
Paul Alvarado
@Robogeek
Bumper sticker of the day: “Buckle up! It makes it harder for the aliens to suck you out of your car.”
1:22 PM · Jun 24, 2008·Twitter Web Client
   
Twitter
Aaron Landry
@s4xton
At the office early. Saw a bumper sticker on I-94 eastbound: “Buckle up: it makes it harder for the aliens to suck you out of your car.”
8:57 AM · Jul 17, 2008·Twitter Web Client
 
Twitter
Amelia
@Amelia_blogger
“Buckle Up.  It makes it harder for the aliens to suck you out of the car.” A bumper sticker
4:55 AM · Jun 7, 2016·Twitter for Android
   
Twitter
N-Spire Me!
@Michael_Rawls
Buckle up… it makes it harder for the aliens to suck you out of your car.
11:56 AM · Aug 14, 2021·Twitter for iPhone
 
Twitter
James Kilcrease
@pimajwktucson
Buckle up,,!  Makes it harder for an alien to suck you out of the car.
11:30 PM · Jan 29, 2022·Twitter for Android