Hi as above have stated . Which programme is more for you when using it to create Mods . which is more easier to understand or to mod.

Zmod for making cars. (Such as adding a lightbar or mapping ELS)

But KevinDV say i can make car by Using 3dsmax

Yeah, but you asked "What do you (as in the members of lcpdfr.com) use to model" and I use Zmod.

haha my bad . sorry

But KevinDV say i can make car by Using 3dsmax

You can make a car in 3DS Max, you still HAVE to use ZModeler to get the car into GTA IV.

ZModeler is required to work with GTA IV car models. 3ds max is required to work with all other GTA IV models. That's only for import/export from/to GTA, though. Other than that, you can easily go between the two. However, in general, people use ZModeler for cars, and 3ds for everything else. 3ds is typically considered easier to use, but if you're not modeling from scratch, it often isn't worth it to go back and forth.