Originally Posted by avanti
I am not sure on what basis you believe that these laws are legally unenforceable. State use taxes are very common in the US, and I have never heard of a successful legal challenge.
Now, PRACTICAL enforcement is another matter, but that is true of a great many laws. But, enforcement of use tax on vehicles is usually pretty straightforward, because collection is typically tied to vehicle registration.
I think you're missing the point. There are venues where the simple possession
of tangible goods is taxed, typically on an annual basis, but sales and compensating use taxes involve the locus of the transaction, not possession. If you purchase something either in your state or out of state for use in your state, it is subject to sales or use tax respectively. But if you are physically in some other state when you make the purchase, there is no sales or use tax applicable because you didn't make the purchase in your home state, and when you return, you might conceivably be subject to a personal property tax but not a sales or use tax.
This is equally applicable to cars, boats and planes that you buy out of state. If you bring them home and store them in your garage, there is no taxable consequence. Where you are hung by the short hairs is that while most states can't stop you from merely possessing
them free of taxes, they do have the power to prevent you from operating
them without registering and paying the taxes they demand.
Were it otherwise, any gee-gaws you buy from a Camping World when you are out of state with your RV could be subject to a use tax when you get home particularly if that Camping World was in a no sales tax state.