Luxior, Giada's Gift is the legendary equipment that Elspeth gets from Giada at the end of the new Capenna storyline.
It has an equip cost for creatures as well as a special one for planeswalkers.
Most importantly there is the clause "Equipped permanent isn't a planeswalker and is a creature in adition to its other types. (Loyalty abilities can still be activated.)"
Aside from shenanigans of turning an opponent's nonplaneswalker-noncreature permanent into a creature until the end of turn and equipping this to it so that at the beginning of next turn it becomes a 0/0 creature and dies (I mean why not just use Murder at that point?) is this a viable method of cheating with vehicles? Vehicles have a printed power and toughness for when they are creatures, and Luxior does not set the base power and toughness of equipped permanent. Thundersteel Colossus as is Honeymoon Hearse and locking a vehicle in as a creature seems like it would have its advantages at times, but I see nothing about this being used in standard this way, nor do I see vehicle decks using this in EDHREC.
Is this nowhere near as good for vehicles as I am imagining or did I possibly find something useful here (I am leaning towards the former).
Neither of your ideas really work the way you want them to. You can only Equip things that you control, so your idea to kill a non-PW, non-creature permanent only works if you can also steal the thing with a Threaten-like effect.
As for your vehicle idea, it doesn't really "cheat" them very much either. While Luxior does have an effect on any permanent it is attached to, the activated ability of Equip only works on a Creature, or for just this card a Planeswalker, and an un-crewed Vehicle is neither of those things. You'd still have to crew or otherwise make the vehicle into a creature first, then you can equip Luxior and it stays a creature past end of turn. Ensoul Artifact or any other artifact animation does the same thing with vehicles, as long as the effect doesn't make the artifacts lose abilities.