i wonder what happen if you don't pay the tickets

i been doing research on this for the past few days.  base on what i read, if you don't plan on going back to europe, there will be no consequences, the european authority cannot just extradite you back to europe for not paying a ticket or tickets in my case.  If you do decide to go back, most likely, you won't be denied of entrance, b/c not paying a ticket is considered as a civil charge not criminal, however, you might run into problem if you try to rent a car under your name, or get pulled over by the european authority while driving on the road. 
im not looking to have a moral discussion on whether one should pay the ticket or not, but does anyone know what happen if you decide not pay the ticket?