Wanna know how to promote your game? With a bus. A giant bus. A giant bus with images of your game plastered all over it. And not just any bus, a Mercedes bus.
A Mercedes bus with TV monitors looping your game's trailer over and over and over again. Upcoming Xbox 360 title Chaos;Head Noah did just that and rolled through Akihabara, where, according to website Akiba Blog the police even said "something" to the bus driver, causing the bus to drive off.
Probably was about stopping so people could congregate and take pictures. With terrible incident earlier this year, Tokyo police are increasingly skiddish about large groups congregating in Akihabara. Understandable.
Chaos;HEAd NoAHの痛バス 「なんてバカな車なんだ」 [Akiba Blog]