Is This For Your 540 Or 325? I Have A Small Vibration Only At 45-50 Mph In My 325. It Got Much More Pronounced When I Installed My New 17's. I Have Already Done The Control Arms And Bushings. All I Have Left Is The Front Hubs, And Strut Inserts/mounts. I'll Let You Know If Either Of These Cured My Issue. My Wheels Are Also Balanced. I've Heard Some Of These Cars Need To Have The Wheels Balanced On The Car, Which Is Expensive, Especially If You Rotate Regularily.