As others have suggested, get a second opinion about whether the tire can be repaired. This is an ultra high performance tire. Frequently, the car manufacturer’s policy is not to repair such tires on the premise that they might fail catastrophically as you blast down the autobahn at 150 mph.
If the tire truly is unrepairable, it would be a shame to put a cheap substitute on a brand new, high end car like yours. Contact Yokohama (www.YokohamaTires.com) to find a local dealer who can get you an exact replacement. Another source is a mail order tire dealer like TireRack. (They have some in stock.) If you go the mail order route, you will have to find someone locally to mount it for you. TireRack has a list of local stores who are willing to install mail order tires.