Forester S Turbo saggy SLS rear suspension
 

I have have a 2002 Forester S Turbo (1997-2002 UK model). I have owned it since new. This model is supposed to have self-levelling rear struts.

It has had saggy rear suspension for some time and I have just had the struts replaced at great expense with original Subaru struts. It is still saggy even with no load. I am now planning to replace the springs with the standard Subaru replacements but I find it hard to believe that these will manage to lift the rear enough. If the springs are weak, the new SLS struts should have pumped themselves up to compensate, in which case the new springs will need to lift the car almost 10cm, which seems unlikely.

The replacement struts, obtained from Subaru, are the same as the originals and they are, therefore, presumably self-levelling. However, other posts on this site say that SLS struts are green and have a reservoir on the outside. My struts are black with no reservoir on the outside. They are installed now so I cannot read what it says on the outside. I have spoken to Subaru in the UK who can offer no useful advice and suggest that the green ones might have been used on Australian models but not UK models. They tell me that the installation instructions are very straightforward, so it is unlikely that the new struts have been wrongly installed. They also tell me that they don't know of anyone with a Forester ever having to replace the springs. But the only other Forester owner that I know also has very saggy rear suspension.

Can anyone shed any light on this? Are new springs likely to solve the problem?