This spring I installed a Harken windward sheeting car on a 28.5 to replace the original track/system. The last 4 bolts to starboard are hidden w/in a cavity (see photo; yes, those are wires I didnt know were there!) and were a bugger to locate and fasten, but the improvement in ease and performance is now proving its worth.

I went w/ variable hole track, so each of the 18 holes on the 3 spacing was accounted for; there is a camber of approx. 3/8 in the mounting surface, so starting in the center and working outward permitted the track to bend-to-fit.