If you plan to add this to your 2011 or newer Apex, please be aware that the stock "thick" washers are larger than those for past years sleds. Those washers will not work with the kit.
When placed on the circlip side of the wheel, the washer rotates against the circlip and locks the wheel up. Pioneer's kit provides an entirely new wheel mount. In order to lower the wheel position, the hole which the wheel mounts to is off center. This in turn makes the bolt that goes through and secures the wheel also off center; thus making the washer off center. This explains why the stock washers (too big) will not work; the elongation rotates the washer high against the circlip. Comprende'?
Anywho, grinding the stock washer was both a pain in the arse, and it still hit the circlip even after removing a lot of material. I opted to spend a bit more money and buy stainless steel washers at the hardware store ($4).
I notified Bruce at Pioneer and he seemed to recall someone else calling in the past about the same issue. He indicated he would probably be adding something on his website to address this problem.
jf