You can just create a texture for it. I mean, obviously you are going to have to 3D Model it, but just UV Unwrap the car model, export it to substance painter, and paint your car model, giving it a cool gradient such as the ones in the pictures.
as @sparker22 said, there isn’t really any way to do this without using any weird hacks, which won’t behave properly under lighting.
That being said, you can use the trick that @PeZsmistic used with the forcefield material, combined with a gradient/rainbow skybox, and reflectance on the car material. Obvious issue with that is that the skybox will look strange, but you can sort of get around that by using an inverted sphere mesh as a replacement for the sky. I wouldn’t recommend it though.
this is the result of using this method, I’ll link the file, you should definitely have a look at it, as the colors change in an extremely fascinating way when you move around the car. I’d also recommend trying out different skyboxes, such as rainbow ones, as by doing so you can increase the number of colours, and can get some extremely cool results