hell, i could make any car rare... just put a scratch on the side and take a crap in it. I bet that would make it is #1 of 1 because how many models have a scratch and a pile of crap in it? i hope not too many.
but it does sound nice, having a rare car. 1 out of 11 is nice, that is rare, but who is gona pay thousands of more dollars just because your car is slightly different? I hope to make my vette #1 of 1 some day (not by the techniqe listed above :L) Maby i could paint it like no other vette has be painted, and put some mods on it, then i have a unique car, but if i ever have to sell it, im not gona add 20k to the price of it, because few are that dumb to buy it.