I orderd some coilovers and they are on the way.Was wondering how much I could lower the car and not have any rubbing issues ,I plan on getting some 18" in a couple of months.

 

I strongly suggest that you go with 17 inch set up I had the 18 inch setup and was dipping into them on the freeway and other spots on the road. Trust me the 17 inch setup is way more effcient than 18s they are lighter and have less problems with rubbing. I got buddy club coil overs and my car is really low and rub even with stock

 

They will work with 18" as long as the size and the offset of the wheels are correct. The tire size would also need to be adjusted to fit the specific wheel you were to choose.
If I can help let me know.