I talked back and forth with an OBX supplier for a few weeks when I was shopping for headers. I was trying to get them for basically nothing to be their step into the Viper world because nobody had used them (at least that would say). I couldn't get them to move very much on price, but what they did offer made me back off anyway. They said that I would have to pay full price and then they would refund me $100 after I wrote positive reviews on the Viper sites. I told them I wanted a discount up front and would 100% write a review, but it would be an HONEST review. If their product was great, I would say so. If it was ****, I would say so. I never heard back.
I ended up going with the M&M's and couldn't be happier. Great product and Matt is a pleasure to deal with.