Kizashi Club

Hello friends! I'm wondering if any of you have found some low cost performance upgrades? I want to squeeze a bit more juice from my 2011 sls. Any recommendations?

I'm also having a hard time finding accessories, specifically rain guards for the side windows, and a wind guard for the rear window. Also interested in an oem low pro spoiler.

Thank you in advance everyone for your suggestions.

Most highly recommend a set of the lightest possible wheels of appropriate size (17X7.5" or 18.X8.5"). There's not much else available, except better brake$.