I have a 2009 JCW that has developed a knocking in front suspension even while driving straight and gets worse on exit ramps banking to left. Its lessoned under acceleration. I had local garage check it and the suspensions is all tight with no visible issues, which leads me to believe it might be a strut, and help would be appreciated.

 

I would say you're correct to think it's a strut issue. Probably right front strut from the sound of it. Since the car's load is on the rear under acceleration and the problem is lessened under acceleration is what leads me to believe it's in the front (and you mentioned left banking it worsens). It is worse under braking or heavy braking? Is any knocking louder or more noticeable when going over a speed bump?