Why would one buy a 486SX? Good question. If one were shopping for a car, you would need to be in the market for a BMW, but you can't really afford it, so your willing to let the dealer take the engine out and put in a Yugo engine instead. Later when you're tired of moving up hills at 5 mph., you go back to the dealer and buy a real BMW which he then bolts the side of your BMW, pats you on the back and asks you how you're going to use all that extra room you have.
(From the "Rest" of RHF)