I installed brand new KW V1's on my Octavia after running a second hand set for a while. From the off they creaked, groaned and knocked despite numerous attempts to fix they were eventually sent back to KW who eventually issued a full refund.
No word of an apology or offer of recompense despite several trips to my tuner who is an hours drive away.
Fit KW or nail my bellend to the desk. Pass me the hammer and nails every time.