Here is how to make a car with a specific body but no spoiler
Change car to Supra (With Art money)
Enter the Aftermarket
Change back to your original car
Freeze hood ("F1")
Freeze spoiler (''F2")
Get bodykit (you will get a bodykit without hood and without spoiler)( exit aftermarket)
--****-change car to the the car you want the body --enter aftermarket---change car to original....choose you special body and buy..you will get the error..press okay
Get out of the aftermarket, if you will get "Error" press ok.
Get to paint shop and change color to your car, save and exit.
NOTICE
i did all this wen i diden't had any spoiler to the car i used ,,aeroaqua---Remove Spoiler: way first then i used this one
It works tested.
Like if it helps