For Calvin (And His Next Two Hitch-hikers) lyrics

[includes a quote from The Adventures Of Greggery Peccary]

Where did they go?
When did they come from?
What has become of them now?
How much was the leakage
From the drain in the night
And who are those dudes
In the back seat of Calvin's car?

Where did they go?
When they got off the car?
Did they go get a sandwich
And eat in the dark?

Submitted by Guest

What do you think is the meaning of For Calvin (And His Next Two Hitch-hikers) by Frank Zappa?