The car shop is in Istanbul called Auto Bilhan. If you do a search on google it should come up.. I'm not home at the moment to search through my history and find it. I did contact them to ask if they knew anything about the exhaust...
I'd be curious to check it out as I want a V8 rumble as opposed to a raspy sound (no disrespect to anyone who likes a raspy exhaust)
I called Eisenmann in Germany and the wait is a month after placing your order as their exhausts are hand made. That doesn't bother me but i'd like to see what other options I have.