As a customer I would expect the fitter (if Bilstein aprroved) to handle the entire process. I would not be reposnible for relationship between the outlet and the manufacturer and my contract of sale would be with the outlet not Bilstein. Thats what separates the good companies from the bad, no manufacturer of any products has no failures, it's how you manage them that separates the good from bad.
I say this as someone who manages a global network of outlets for an Aero Manufacturer, if our customers use one of our partners we sort it with the partner unless it's customer damage. Most of the time we cover it, sometimes the partner if it's something out of our control and in theirs, but it's down to how the manufacturer manages the relationship with their partners and who they select. We select ours on technical capability and trust thier judgement (audited peridoically to make sure were all on the same page).
The end user experince is key, that's what get the reputation, repeat business and growth through word of mouth.
