> Is the purchase of each additional car going to increase the tax paid?
Yes, tax liability = total spending during the year plugged into the power law tax formula.
>Are exotic cars taxed more?
Depends how much the taxpayer spends in a year. There is no tax rate for each specific item. The tax rate is for a total level of spending, which eliminates all loopholes.
> You keep stating to use a power law formula but you're critically omitting what the inputs are to determine your tax rate.
The input is total spend in a year. Just like right now, the input is income in a year.
> And now you've also admitted that assets determine your sales tax
No, I did not. The formula to calculate sales tax liability only requires inputting total spending. Land value taxes are a separate thing. We currently have land value taxes, except they are flat rate and too low because property taxes inefficiently tax improvements on the land more than the land itself.
> That's why the income tax is effective - it's taxation at the moment the money changes hands / you've realized a gain.
Sales tax can also be at the moment the money changes hands. It currently is. Even with the complication of a power law tax formula, I can’t see why the government can’t email you a monthly invoice.