What size spacer is needed to make the stock sport wheels/tires sit 'flush'?

They're 18x7.5 et45 (F) and 18x8.5 et50 (R)...

15mm f/r or 20mm f/r or a mix?

http://www.conceptzperformance.com/C...3969.76.220.77

I'd go +20 F and R if you're lowered and +15 F and R if you're not lowered.

skinny wheels, need to add an inch to both (width wise)...

*edit*

nevermind, i just figured out how offset numbers work. lol

18x8.5 et50 w/ a 20mm spacer = 18x8.5 et30. I wasn't sure if it moved in or out as et increased decreased.

this is a cool little tool http://www.1010tires.com/WheelOffsetCalculator.asp

Looks like 20mm w/ a drop would be perfect.

Pretty much the same stance as this: (20mm front / 19mm rear)

https://g35driver.com/forums/media-share-v36-sedan/173844-my-07-finally-rims-drop.html