By Tobias Carroll Here’s a riddle for you: when is a Lamborghini Diablo GT not a Lamborghini Diablo GT? The answer, in this is case, is simple: when it’s actually a heavily modified Acura NSX. Head on over to eBay Motors and you’ll see a listing for what appears to be a sleek black Lamborghini with an asking price of $175,000. Take a closer look, however, and you might start to notice a couple of variations here and there. As the seller explained in the listing, that’s no accident. The car is the work of an expert craftsman whose work has appeared on film — specifically, the Vaydor driven by J…