We already sell the repair panels for the trailing arm outer mounts as part of the Jacking Point repair panels (Left and Right), but the inner mounts are also available...
On the webshop you'll find something which appears to be an "Inner Outer Mount"...
Bear with us here...
The trailing arms have 2 mounting points to the chassis. The outers are just in front of the road wheel, the inners hang from the chassis.
Now the inner mounting are made up of parts...
The part which forms the inside of the mounting point, the part that forms the outside of the mounting point, and a brace which goes between the mounting and the side of the chassis.
Serious rust in any of these will result in an MOT failure. And rightly so!
So... if you have corrosion just the outer section, you can replace it with these:
However... if the corrosion is in the inner section, you need one of these:
As the outer part is welded to the rest, the "inner" section already has the outer section attached.
Clear as mud? Good.
Just to confuse the issue more... the third part is seperate, and braces the complete mounting to the chassis.
So... if you were replacing the lot, it would likely make more sense to get the bracing section too. If you're just doing the outer section, you wont need it.