We would love to sell trailing arms to anybody that's buying.
Unfortunately our shop/production has been at full capacity since summer 2011 and hasn't stopped. We haven't had much time to do any new projects until now. Our schedule has started to clear up and we are starting production on items like trailing arms. Currently we are only working on the narrow width trailing arms.
In regards to the suspension on the Coastal XP, it has always been for sale. In fact, we have sold a few kits to serious buyers. Anybody who would have inquired about it would have been told how much it costs and what it includes. One would have also been told it's not a stock replacement kit, therefore requires a larger investment and some modifications to the RZR-XP in order to use it.
Moving forward; We will soon be offering a Narrow 'XC' suspension for the RZR-XP. (the sole purpose of this thread is to announce our intentions to sell such a product)
We may offer a standard width stock replacement trailing arm in the future, but it is not in production right now and we do not have an ETA.
We do not plan to build any suspension that is wider than the current stock XP suspension. Wider does not necessarily make it better, the stock XP is plenty wide and there are other ways to improve handling.