Yes, please do Google MFactory LSD; You will be surprised at what you find. One other thing, generally, when someone is happy with a product, 90% won't say anything about it. However, when someone is not happy about a product, 90% of the time, they will say something about it. Because of this, yes, I agree with you, you will find it impossible to find thousands of "happy customers" by searching online.
However, what you will find when you do Google MFactory LSD, is that the other 10% of happy people will have posted up about our company and our product, whereas you will not find very many "unhappy" people (and those that you do find, we have always sorted any issues with them. We stand behind our product 100%)
We are 100% committed to making the 350/370Z fitment, so here's what I will offer someone on this forum, should they decide to accept:
I will send the prototype of our 350/370Z Helical LSD
Free of Charge for test fitment and review; Yes, absolutely free of charge, under the following conditions:
1) The tester will work with us to ensure 100% fitment and function of the LSD. Tester must be willing, have time and experience of installing differentials in the 350/370Z
2) If, after testing, you find the quality of the product to your approval, you will be required to provide an online review
3) Of course, the LSD is yours to keep and use
PM me if you think you are a suitable candidate for R&D