I didn't use any spacers as those would push the wheels out even further. Both the front and the rear have a 25 offset. The rear tires are 225/40/18 so they have some stretch which helps with the clearance. I didn't have any rubbing on my 2012 Leaf, the black one, as the fender has basically no lip. But I now have a 2016 Leaf and the rear fender has a large lip so with the rear adjusted all the way down they will rub occasionally. I fabricated a rubber bump stop to limit the suspension compression which prevents the tires from rubbing but rolling the fender would be your best bet.
For the front I have the suspension all the way down, the tires are 215/40/18. The only time they rub, and only on the inner fender liner, is if you are entering a driveway at an odd angle. I have had a previous tire of the same size, different brand, that did rub fairly often so I had to raise the suspension a 1/4 inch or so.
Here is the 2016 Leaf with the same wheels, painted a different color.