This is the Pegassi Tempesta made to look like the Joker's car from Suicide Squad.
All i did was modify the wheels/rims, license plate, and removed the spoiler.
Just take the car to a tuning shop and paint both primary and secondary colors purple.
Rims are already painted gold.
I think the Pegassi Tempesta is the closest to the Joker's car.
Rename the files and replace whatever car you want.
If you want neon lights under the car, i included a particle.txd file for neon.