I say try oven cleaner, let it soak for awhile and it should remove the paint you applied, if it ends up removing the original paint, look at it as a bonus. But use gloves cause oven cleaner isn't bad for the skin.
There is really no way to remove just one layer of paint without affecting the layer beneath it to one extent or another. You can try oven cleaner, but it will affect the paint beneath it. It may weaken the paint or make it tacky and gummy. What ever the effect is it will most likely remove any gloss wich inturn will have to be adressed. You're far better of just stripping the car and starting from scratch.