Replacing front air struts has not cured the problem. So how do I access/check the rear suspension?

 

Well, if you tell us more about your problem we may be able to give additional help. The rear struts top fastenings will be found in the trunk, but you'll have to take the side trim pieces off, unlke the fronts where they are easily seen in the engine compartment. At the bottom, you'll need to get the car reasonably high of the ground, with a wheel off when you'll be able to see the lower fixing which is much easier to undo than the fronts, but the spring unit can be difficult to wiggle out., (or so I'm told !!).
If you've replaced the front air spring struts and it hasn't cured the problem, this illustrates the danger of throwing parts at a car before a full inspection and diagnosis has been done

 

As stated above, what problem? It might not be a strut problem at all?

If you don't have a scan tool that can read the Air Suspension Module, then you're guessing, and that will be even more expensive than guided troubleshooting.

 

Mark,
The full service manual is in the stickies - it will walk you through diagnosis and repair

Also in stickies are routine repair write ups - including air suspension

(I would guess that 80% of posts on this forum are fully addressed in the stickies. They're a wonderful tool...)