The rules are pretty clear here, if you add enough Orichalcum you can enchant anything, a barrel of toxic waste even. The reason you don't see this is because it's just too damn expensive. But if the player has 600 large then they should be able to spend it as they see fit. If you spent 880,000 nuyen on 10 units of Orichalcum, then you could feasibly negate the Object Resistance Rating of the car. Of course, why would you spend that much money on something like that. Anything can be enchanted, anything, just like you can ward anything, or cast a spell on anything, you just have to deal with the penalties involved. Fortunately, if this particular stick bothers you, you can feel relieved to know most players never play magic-users, let alone use enchanting to any effect.