I just bought an 03 cobra with the Mach 1 chin spoiler on it. I personally don't like the way it fits so I took it off. Cobra chin spoiler is the only way to go IMO but man that's some expensive "plastic".
You can get real Carbon Fiber for the price of the oem rubber - seriously. If you need one really bad, I would put up a want to buy and possibly someone with a super low mile car will sell their stocker so they can upgrade to CF.
They used to make them. I have one. It isn't as nice as stock but you wouldn't know it unless you laid down under the lip and looked close. I can't seem to find it on their site anymore though. Might be worth a phone call. It was $200 free shipping from their Amazon store.