I've been looking for some 18" for my MY04+ for some time now.

5Zigen now has available offsets that will work for our car. (this might have been out for a while but it's news to me)

18X7.5 +48
18X8.5 +48

with the correct bolt configuration.

Now I have to find some tires. I'm going to lower it about and inch but I believe that I will have to keep the stock widths on the tires to prevent rubbing. I would like more traction but these rims are mostly for looks and I'm already losing performance because of the weights.

Any recommendations from people running the following tire sizes?
215/40 18 front
245/35 18 back

also, do you think I should get 205 on the front seeing that the stock RE50's are so wide in reality?

 

The offsets you have are going to be tight at the fenders. The only thing I have available would be the BF Goodrich KDW2 in the sizes you mentioned. I would not go any wider that the sizes you mentioned. either.
If I can help let me know.