Hi all,
apart from using line of sight/a good eye etc (which I'm not averse too), is there a trick to fitting the rear wheelarches to ensure that the wheel is centrally located?

Make sure car is grounded (on wheels) for a start and bones parallel to floor as it makes things easier.

Place front and rear lip of arch to lower edge of sidepanel and rear panel. Position for centre using a ruler (or by eye) then rivnut and nut/bolt into place.

Steve

Do it the Egyptian method ! A piece of string attached to the centre of the driveshaft, then use it to measure the radius to the wheel arch. But as above, ensure wishbones are in a parallel position for this.

I used jacknuts as mounting points for the arches. They're designed with a much lower fixing point than rivnuts and are perfect for fibreglass.

I would lower the rear of the car onto it's bump stops and the place two pieces of say 15 to 20 mm thick wood at say 10o'clock and 2'oclock on the tyre and then set the wing on them. Rotate to the position that looks best/is legal and check that it's not rubbing on the tyre at any point.