The Key to Ultimate Happiness is the Back End of a Car

I've seen this commercial a dozen times while watching tv on Amazon Prime.  I don't understand it at all.

A lot of extremely delighted people are walking out of their houses and into the streets, and eventually into rugged mountains, while singing the 1968 classic "Nah Nah Hey Hey Kiss Him Goodbye," by the one-hit-wonder rock band Steam.   

I first saw the commercial shortly after the 2020 presidential election, and thought they were saying goodbye to Donald Trump.  But why are they carrying the back ends of cars?

Meanwhile, on a high mountaintop, an extremely delighted cowboy opens the back end of his truck and stands on it, gazing down on the culmination of all of his hopes and dreams.  This is it!  Ultimate happiness!  Paradise!

Then the narrator says some gibberish very quickly: 3.9% APR financing sasquatch Armageddon hatchback tailgate $5000 authorized macadamia nut financing available Ford marshmallow today!

After a few viewings and some internet research, I figured out that the procession is carrying the back end of a truck that slides down.  It's called a tailgate, like the parties they have in the parking lots of sports stadiums!

The crowd has achieved ultimate happiness because they can replace their old, horrible "tailgate" with a new, wondrous one that will solve all of the world's problems.

But I still don't understand.  Are you supposed to take your old tailgate to the car dealership, get the new happiness-inducing one, and install it yourself?  Or do you have to buy a whole new car?   If you have to buy a new car, why did they take off the old tailgate?  Wouldn't that reduce the trade-in value?  And why are they walking hundreds of miles through the desert heat with the old tailgate?  Where are they going?  

I guess you have to be heterosexual to understand.

In gay communities, you either don't own a car at all, or it is a means of transportation.  Company, style, APR, PRB, trans-world steering, ranglefraz interior, multiple stereo gizmos, and tailgate type are not happiness-inducing.  They are irrelevent.  No one ever says "Hey, the guy in the Ford Bronco XLX 397 is cute."  At most it's "The guy in the blue car is cute."

At least the song has a gay connotation. Although most of the songs on Steam's only album are about girls! girls! girls!, the cover of "Na Na Hey Hey" depicts six hippies naked in a bathhouse.