Computer case neon VS Automobile Neon

Now that I look at my diagram carefully, I think I wired them in series and not parallel.  But the reason I thought you cant wire them in parallel is because the transformer or inverter (if they are the same thing)  can only hold a max of two neons.  This is where the confusion occurs.  Here is a link to how the Oznium website says to wire them.  Take a look at the second diagram with the transformer  located outside the neons. 

http://www.oznium.com/forum/topic20

The only show one , with four neons.  Someone please explain why I would not have to use two transformers or inverters.  And one more thing, is the transformer the same thing as the inverter that comes with the neons???