I had a st40 kit on my old car. I decided to do the same for my new one. First thing I noticed was my rotors make noise. After some research I found out my rotors are floating. My old ones had spring washers.

2nd thing was that after install the rotor wasn’t flat. It almost wobbled in one spot. Everything looked great and tight. Even tightened all the lugs.

I checked run out and it was off the charts. I put the stock rotor back and checked and same issue. Checked the hub and .002 run out. No issues.

turns out the rust on the center hub was sticking out just enough to cause some issues. I dremel It off and back to normal. I only took off a few high spots. Just a reminder to check