Here's a few for starters:

Single version of "Forever Autumn" (from War of the Worlds):

Just after the electric guitar solo into "'cause you're not here."

Single version of "Baker Street" by Gerry Rafferty

Mellotron drops in from nowhere just before guitar solo

"Shirt" by the Bonzo Dog Doodah Band

Lots during street interview section at beginning - traffic noise very discontinuous.

Any more guys?