Texture and polygon questions

[_HighVoltage_]

I've started working on Zailer's Volvo 850 in an attempt to finish it and make it accurate.

 

Somethings have worked...others have not.

 

First question - can I add addtitional texture files, or can I only edit the current ones?

 

Secondly - the headlights on the car are very dark, no matter what I do to the texture. I think there is GLASS over the texture. Where can I find that and remove it? Is it something about the alpha blending?

This is the extent of my problem:

-- OLD IMAGE REMOVED (imageshack) --

 

 

Also, how come even though I removed the second exhaust from the model (it's not there when I import it again). In game - there are still two exhausts?

 

 

My last question is a big one - how to add new polygons in Zmodeler?

 

I was able to erase certain ones, select others, but as far as changing them - no luck... I want to fix the front splitter of the car, so essentially I need to add stuff to the bumper. How do I create polygons in Zmodeler?