Pettan alone means flat. For example, the suffix -ko means "girl" (such as in meganeko, megane = glasses so glasses girl) so pettanko means a flat (chested) girl.
As for the Japanese look, there's three main points of the way modified cars should look (in Japan), and that's onikyan (cambered wheels), tsuraichi (tires just barely inside the guards) and hippari (stretched tires).
Japanese for flat chest.
And probably one of the most addictive songs in the world.
(weeaboo1): THAT GIRL IS SO KAWAAAAAAAAAAAAAIIIIIIIIII!!! (^-^)
(weeaboo2): HAI, BUT SHES A TSURUPETTAN
(^-^)
a few seconds of silence...
(weeaboo1 and 2): KAWAAAAAAAAAIIIIIIII!!!!!
Similar to “sure” but the “t” emphasizes how pissed of you are at the statement or request made. Also emphasizes how much you don’t give a shit about what the person said.