This Is Not Just A Towel, This Is An M&S Towel.
The Hoopy Froods towel of choice
"The contents of Ford Prefect's satchel were quite interesting, in fact, and would have made any Earth physicist's eyes pop out of his head, which is why he always concealed them by keeping a couple of ... Beneath that in Ford Prefect's satchel were a few biros, a notepad, and a largish bath towel from Marks and Spencer."
Shame we lost the towel.
What happened to it?
It blew away in the wind. Fell in the river and a stream of lava rolled over it.
Hah, it’ll give the archaeologists something to think about: “prehistoric towel discovered in lava flow. Was God a Marks and Spencers sales assistant?” What are you doing Arthur?