I hear on the W126, the bracket that supports the air filter and the bolts and heat insulators are prone to breaking. Mine is broken. I ordered a new bracket and insulators from **************.com. You can order from them, the bolts/heat shields in a kit which includes a "sound quieter" - basically a short bit of plyable hose that you drill and screw into the side of your air filter so if engine vibrations make it bang against your engine, this "bumper" will instead absorb the impact, making this quiet and last longer. I got it in the mail last week. Quality looks fine, even better is a decent instruction sheet on how to install, complete with pictures.

I hope this helps! I hope to install mine in about 2 weeks when I have another weekend available to work on it.

Take care,

Robert