In the process of making my FX more trail worthy, I've realized that the rear fender may not be strong enough to withstand being pulled to lift the bike out of a rut, over a log, etc. The easiest solution is probably a rear lift strap, as shown on the MMX.
But... Zero is charging over $100 for these little straps, which I couldn't justify.
http://www.zeromotorcycles.com/high-res-photos/photo.php?img=2014:2014_zero-mmx_studio_lp-wbg
Looking closely, the Zero strap appears to be similar (maybe identical) to this universal Moose product that sells for $25. This seems like a great alternative?
http://www.mooseracing.com/products/?productGroupId=1136
But... Once I started thinking about how much something like this should cost, I decided to make my own using two of these:
http://www.ebay.com/itm/201426881529
Having invested about $3 and one hour of sewing, here's the final product. The brackets fit perfectly under the side panels and the length is custom set to my preference. Very pleased with the outcome. Hopefully this info helps someone else too.
P.S. I received my 2013 MX seat today too, which is softer and taller than the FX seat, and most importantly lets you shift your weight forward or back as needed when off roading. Cost for the MX seat was more reasonable, at ~$112 shipped. Thank you
rayivers for the suggestion.