The tax laws on mail order sales in most states are that the vendor (seller) has no obligation to collect state sales tax for a location (other state) in which the seller has no permanent business location (a "nexus", in legal parlance).
The BUYER, on the other hand, is subject in every state of which I am aware, to PAY a "use tax" which is more or less a "reverse sales tax," since it is the same amount as one's local sales tax rate.
Now, as a practical matter, almost no one volunteers to pay this tax to their state of residency. Some states have begun toughening up on this. In North Carolina, as one example, (and I hear several others will be adding this feature soon) there is now a line on the State Income Tax Return, that one must total all out-of-state purchases, and add (and pay) the amount due on all merchandise purchased out of state (whether ordered by mail, or picked up in person). This wrinkle is more odious, since one signs and files a State Income Tax return under penalty of perjury.
I have heard that New York state tax collectors are so hard up, that they send spies to the large malls right over the border in Pennsylvania, with cameras to photograph all the license plates of NY shoppers there. Later, they match the license plates with the owners, and send them a letter "inviting" them to pay any tax due.
What the dealer has informed you about, is that whenever a purchase is made using installment credit, the seller MAY file a UUC (Uniform Commercial Code) form which makes a public record of the finacial transaction. The reason this is done is to create a lien against the title, so that the owner who is financing his purchase cannot legally sell the vehicle or equipment, until it is paid for. Often, sellers do not file UCC's, but for a piece of equipment costing $20,000, they most likely would.
As the Romans used to say, "Caveat emptor" (buyer beware).
BobT.
A Indiana Boy