You may have the answer I am looking for. I want to clarify this with you.
If i got bc coilovers and 20" wheels with 30 wall that would be equal to stock tire diameter or close? Thus would be able to be lowered with the coilovers as if I was on stock wheels and tires (same height) and make it look pretty nice do to the large wheels/skinny tires. Correct me if I am wrong or have any concerns with that plan.

What are peoples experiences on spacers and/or wheel width on the x's. Is there any clearances I need to watch out for with wider rims? Rolled fenders or anything else.

Does anyone have any pictures or experience with this set up? Thoughts on ride comfort?

 

Yes the wheel and tire setup should be equal to stock tire diameter and shouldn't cause any issues. Post pics of your new setup.

 

I have an 08 G35x, I live in the DC/Baltimore area. ROADs SUCK. Factory sidewall on the 16" is 4.87". So I am on eibach lowering spring and the front is approximately 1" lower than the rear. My Under carraige tray was also draging, but I need it so I put the car up and bought more bolts and put it all up, the rest i ziptied.

The rear of the car, I took off the UPPER spring seats and cut 1/2" inch off. The car is more even now.

because the travel on my springs is less I didn't want to sacrifice quality of ride I stuck with being as close as possible to the tire sidewall to factory. I am going with 19" rims/tires 255/45/19 tires. overall increase is 2" from OEM. So withthe 1.5" drop and 1" from wheel I am close to factory. Car still looks low and gives the aggressive style but ride is smooth.