Midnight said:
Bilstein work with H&R on a few different components. H&R struts 'were' originally Bilstein.
BC are a rebranded KSport, YellowSpeed, XYZ, D2 which originates from Tein copied struts. (Day 1, may have changed slightly now).
That's not saying that some have revised parts but most the above are made in bulk in similar warehouses.
(We run Yellowspeed Area MS coilovers, again while they share some companonets some parts are researched and upgraded to offer better results e.g Eibach rear springs).
I remember when XYZ/D2 first started they were looking for smaller companies to brand out. So if you had the ££,£££ you could have had very similar suspension/brakes but with the Logo 'Chris' and have your own brand.