Ah, I see where the confusion comes from. You mean when the audio equipment is taxed higher than the car. I think OP did not mean "put 0 tax on cars" but rathe

Ah, I see where the confusion comes from. You mean when the audio equipment is taxed higher than the car. I think OP did not mean "put 0 tax on cars" but rather remove the extra 100% tax on cars, so it's just taxed like any other product - i.e. just the same as tax on audio equipment. Then it would not matter.