Good to see you are getting stuck in mate. people have their own different ways of converting. personally i think you have done well. export each part you have from zmodeler 2 as .Z3d parts and then open with zmodeler 107.
open each part individually in zmodeler 107 and make sure the dds file is replaced with the tga version, also make sure the UV mapping is correct at this point.
Once this has been completed either merge all the .Z3d files into zmodeler 107 and then export as .GP4 file or
Export all parts as .GP4 files and then open and add .GP4 files to make the whole car. when the whole car is in gp4 builder you can split it up and rename parts in to the 28 parts needed.
note the front wing is 4 parts
left wing
right wing
left front fin
right front fin.
people are very good on here and will give you the way they do this probably faster and easier than my explanation
good luck
