zero wheel clearance, need advice on max deflection

[rwalker]

I've just mounted a set of D-Force ltw5s, 18x9 ET41. The fronts clear my struts by maybe 1mm in stasis (see pics). Unfortunately, under load and deflection, they rub on the struts (nice noise ). Tires are 255/35r18 Toyo Proxes R888s, and have plenty of strut clearance.

So: I'm shopping for spacers, and would like to run the absolute minimum thickness required, to maintain maximum fender clearance.

My question: does anybody have experience with the amount of hub deflection, wheel deflection and strut/knuckle bending I should account for with 18s? I'd love to get away with 3mm H&Rs.

If I use a 3mm spacer, that should give me:

arcsin(3/(9*25.4)) = ~0.75 deg deflection

Sounds like plenty, no? Would love some input.

Another option I've considered is grinding away a bit of the wheel lip. Anybody every try that?

Pics below. I'm running stock Sports Package suspension with M3 control arms aligned to maximum negative camber (camber pins removed), which seems to providing plenty of fender clearance under compression right now. Here are a lot of pics in a movie to show fender clearance under some compression (left rear of car jacked up maybe 18"):