Seriously your saving pennies by trying to escape the sales tax it is not worth the aggrivation your going to find yourself in.
North Carolina for instance has a 3% sales tax on vehicles and commercial vehicles cut off at $1,000.00 thats the most one would pay.
Now what the back lash would be if I tried to escape that? I do not know I do not want to know cause I am going to do things in running a business on the straight up and up. For instance what did you go thru and pay for the LLC? People think as you are that there is a way to escape taxation, defere it maybee but your gona pay sooner or later. And in the Eyes of the Govt. Sooner is always better for the payer as penalties, intrest etc.... etc....
Now what is legal? This is my story for today. I just purchased a trailer, used. I can Title and register that in Maine for $210.00 for five years not each year but for five. Tractors, straight trucks, etc.... Better be Titled in ones home state.
IRP your carrier will only supply you with the miles and give you the paper work for you to file these. If your gona run Expedite I purchased all 48, and 8 Provinces, BC AB MB SK ON QC NB NS it was maybee $2.00 for each Province. Very inexpensive as to run in NS alone is over one hundred for a three day temp. That one load you never thought you get, I GOT.
Another reason for your own state, Good luck on getting that IRP when you live in lets say IL, and Title or Register it in MT. Just my two cents.