Well you know what an Itasha (痛車) is but what do you call one of these?
These are known as Itachari (痛チャリ) and can usually be seen dotted around Akihabara.
痛 (ita) = pain
チャリ (chari) = Bike
So why are cars or bikes that are plastered with anime characters labeled with the word "pain" ?
In Japan, Otaku are still looked down upon as being uncool and having these stickers on ones car or bike is seen as "painfully embarrassing" - so now you know.
Looks cool to me though and would love to do my bike up like this. Picture taken of this Sumomo Itachari by Frankie.