I've noticed some people have used dzus fasteners near where the front clip meets the bottom of the spider. Could someone let me know if this is necessary and what the purpose is for?
Probably not absolutely necessary, but I have them as it stops the centre of the front clip lifting at speed, and is an extra safety measure if one forgets to fasten either of the side Hartwells.
In order to get my front clip and spider to align correctly I added two alignment bumpers midway between the center of the spider and the fuel caps. I built standoffs for the two dzus fasteners and set them at an angle so the slots in the dzus fasteners line up perpendicular to the center line of the car. If you add the bumpers and the dzus fasteners you can zero it in for a perfect fit.