Wheels should fit, but they don't?

OptionZero

Are we still talking about brake clearance, or are you just interested in wheel fitment?

Your math is correct, a 20mm spacer on a +24 wheel will make it +4

A 9.5 wheel, +4 offset is going to stick out ALOT more than your rears, and will require around -2.5 to -3 camber to clear the fender, depending on height and tire size. For reference, a +4 front will stick out 36mm more than stock but the rears will only be 11mm more than stock (comparison to stock Nismo wheels)

There is zero camber adjustment in the front, so you absolutely need front upper control arms.

here's your homework:
Wheel Fitment 101: START HERE

Read that thread

Figure out whether you're going to get a replacement face and what the offset will be (Work can do this for you, i assume) OR if you're going to slap on a bigass spacer (don't do this, it's dumb, and probably need the bolt-on kind or extended studs)

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