Nebraska, like many states, allows collector vehicles to receive special registration. Think of it like a state “show and display” law. The wording in the legislation makes no mention of any perks for the owner, just that you pay extra and aren’t supposed to drive the car as much or use it for normal things. No really, that’s about as specific as it gets. It’s vague enough that this lovely but seemingly unremarkable 2006 BMW 330i sedan is somehow registered as a “special interest vehicle”.
The only advantage I can come up with is that special interest vehicles are only required to have one plate; normal cars must have both. I know most of us on here think front plates absolutely ruin a cars looks, so that could possible be a reason.
EDIT: As Hammerheadfistpunch pointed out, insurance on a “collector” registered vehicle is usually a lot cheaper than on a normal vehicle, so that’s probably why.