if this is a 'case' in regards to what happened to you 3 years ago, then you are definently going to need strength in numbers, as your case has no merit.
Are you going to sue Specialty Z over a loose downpipe too? Is it their fault? How about the guy who welds the downpipes? surely you'll include him. What about the guy who made the nut that backed off? OMG he's negligent.
I've been listening to this story go around and around for 3 years and it continues to gain 'laughability' value.