Ok now, don't jump to conclusions... maximum penetration is a marketing term used in business talk. It just happens to suggest something else as well...
Chris Rainbow and Max Middleton jumped at the chance to make a lengthy 12 inch disco/dance record, hoping everyone would buy it. The original was released on 12 and 7 inch on Sidewalk Records (EMI) in 1980. Unfortunately, it was a flop... The single was rereleased in Japan on EM records as a 12 inch as The Instrumental Chris Rainbow EP. Hmmm? Catch the typo? No, Marilyn Martin didn't sing vocals on this one. It was Ian's wife Marilyn Bairnson also known as Marylin Miller.

Tracks Ian Plays On
Maximum Penetration
Maximum Penetration Part 2