(13 May 2015, 5:22 pm)AIG20 wrote Stagecoach Merseyside have acquired an ADL E400 MMC - numbered 80027 and registered "YY15 HJZ".
https://www.flickr.com/photos/80127860@N03/16980441094
Image owned by Flickr user "1dannyandy1".
Edit: Apparently it is one of only two diesel buses in the UK to feature stop/start technology.
I shall guess that this is a Demonstrator, purely by the Fleet Number it has been given.