Although the University of Kent shuttle currently operated by Crosskeys has gained a fair bit of attention, those operated on behalf of the University of Greenwich at the other end of the site by Centaur seem to have largely slipped under the radar, despite being the home to some "interesting" vehicles.
The University is not a bad site for photography if the sun is in the right place (it tends not to be in the afternoon, as the bus stops have the front of the vehicles facing east, with the sun behind them), and the only ever occasion I've been asked "what I was up to" I was advised that they only really pay attention if you're taking commercial-quality photographs of the university buildings.
The Greenwich shuttle itself tends to be home of the more interesting vehicles, and although standard Mercedes Tourismos often appear, various forms of electric coaches are also regular performers. YD73 FRK, a rather unusual looking Yutong ZK6121, with a "low"-looking body and C50D seating (at least so says Buslistsontheweb) was waiting time outside the Pembroke building on Monday 19th May.
The Avery Hill service runs less frequently, and is usually the preserve of various minibuses. At the bus stops (see earlier comment on sun!) on 9th May was Iveco MK69 LPY.
Both services are now on their reduced vacation service timetable until the new term starts in September. (0720.0900.1315.1715 to Greenwich, 0900.1315.1715 to Avery Hill)
Chris