Strange noise when it's hot out???
 

I'm driving a 2003 Sedan with 2005 350Z struts and springs. Got the components from Jason at Performance Nissan, brand new, about 6 months ago. Here in the PacNW, it's just beginning to get summertime-hot.

I take the same route home every day, and now on days over 80 degrees, my front passenger-side corner makes groaning noises when I go over speed bumps. The sounds occur on the rebound bounce and sound rubbery, not metallic. I'm unable to reproduce the sounds by pushing on the corners myself.

Any ideas what this might be? Other than the sounds, it doesn't feel like anything is wrong. It *only* happens when it's hot - otherwise, no problems.