I have lowered my s-line 35mm on H&R springs which I'm told is 10mm lower than it was I have also fitted 12mm wheel spacers to the rear and 10mm to the front and have found that the drivers side rear is hitting the wheel arch when I have passengers (only just on the outside of the tyre but sounds bad inside the car) had 4 wheel aliment done thinking this would sort it but it hasn't. I'm now thinking that the shocks may need replacing as they aren't giving enough damping any ideas on this? And what shocks should I fit?  

If the damping is inadequate then by all means fit new shock absorbers, (poor damping would in any case be an MOT failure,) but they will do nothing for the ride height or wheel spacing. The only solutions that occur to me are longer springs, removal of wheel spacers, or extended wheel arches.

Thanks for replying the car had a mot a few months ago all good and it was this set up, I checked clearance and the wheel fits inside the arch I also took advise on the spacers before purchasing them so haven't gone to wide just seams strange that only 1 wheel rubs under load.