Bilstein makes the shocks for H&R. H&R makes the exterior strut casting, suspension mount points and everything else.
I had a terrible experience with H&R coilovers which I mentioned in another thread. The suspension shaft had play in it after using it for 3 months which made all sorts of clunking noises. You could grab the shock body by hand and it would wiggle - that was how bad it was. H&R replaced it under warranty after much complaining and escalation. The 2nd shock developed the exact same problem within a few months.
I can understand suspension breaking over time but failure to even last 3 months!? I've had Megan Racing (crap) coilovers that last longer than that.