Found a video of former DB type Bpmz IC coaches in service for Bulgarian state railway BDZ. They were purchased just a few months ago if I remember correctly.
https://www.youtube.com/watch?v=pT1PyeA42xA>>2005769It was tested in Germany during the early 90s as well with two dining cars and called "McTrain", but stopped after a year since demand was too low to make it worthwile. Nowadays it's not really a viable concept anymore, because every bigger city with an IC or highspeed train stop will likely have at least one fastfood restaurant available for travellers.