Part Two...
INSTALLATION
Car Location: x64e - levels - gta5 - vehicles.rpf
Car Modifications Location:
x64i - levels - gta5 - vehiclemods
ONLY THE SPOILERS ARE WORKING!
Handling Location:
You can replace the file i provided in the Handling folder in
update - update.rpf - common - data
OR
Follow the instructions provided in the file in order to edit the handling.meta file.
Done.