Letters Back to Ancient China (Dedalus Europe 1997)

Blurb

Mrs. Kei-kung is a thoroughly modern woman and she introduces Kao-tai, a 10th century Chinese mandarin marooned in modern day Munich by his time machine, to the joys of modern sex and champagne. However everything else he encounters is not to his taste.
In his letters back to his friend in the 10th century Middle Kingdom, he expresses his horror at the noise, stench and filth of 20th century civilisation.