I'm missing a couple of lines... can you help? (And what is the meaning of "yodeling up the canyon is the dirty old blue boar"?

WATFORD GAP (Roy Harper)

Just about a mile from where the motorways all merge
You can view the national edifice, the monumental splurge
It's the lonesome traveler's rotgut or bacteria's revenge
The great plastic spectacular descendant of Stonehenge
The people come to worship on their death-defying wheels
Fancy dressed as shovels for their death-defying meals

CH: It's the Watford Gap, the Watford Gap
Plate of grease and a load of crap

At 1 a.m. on Sunday you can hear the boys declare
That the other team were fairies and the ref was Fred Astaire
It's Chopper Ronnie's fan club on their weekly pilgrimage
To stick the hero's boot in all the way from Stamford Bridge
And without a solid concrete burger no night is complete
Plastic cups of used bath water wash away defeat (CH)

The traffic jam is rattling like a five-mile cornered snake
With fuming pieces falling off and steaming in its wake
??????????
Spaghetti junction ????????
The countryside is ravaged like a syphilitic whore
And yodeling up the canyon is the dirty old blue boar (CH)


Cheers,
Michael