I don't know too much about rims and the fitment on the rx8 so thought I post here. I am looking to buy 18x8 racing hart c4 with 38 offset. Would that work well with the 8? I was also planning on springs to lower it a bit too. Thanks.

 

Yes that will work just fine with room to spare.

See if you can get a 18x9 +40 in that wheel or higher offset. Run a 245/40/18 and you're good to go.

Rishie