Genuine Nissan ones are relatively hard to find new. You'd be able to pick one up new from japan somewhere, but it would be stupidly priced. You could probably pick one up on ebay every now and then, for sale section here or wreckers. I'm in the process of replacing my one (only cause I'm an ass of a perfectionist) with one made with carbon fibre, currently talking to one supplier at the moment. If you're interested, I can help you once I test fit my one. Genuine, your looking at around $800+, even for seconds. You can imagine the cost of a new one.