How hard was the install? That diffuser looks awesome.
I bought the kit and I recommend it https://www.ecstuning.com/b-genuine...parts/tcr-rear-diffuser-kit/5g6807568ag041kt/
Really easy, I jacked up the car for convenience but you dont really need to per se. I detailed the process here https://www.golfmk7.com/forums/index.php?threads/mk7-5-rear-valance-removal.374610/post-7500234
The TCR diffuser is very aggressive though, it sticks out and is very noticeable (which is good) - The downside is that if you just put the diffuser on it looks a bit out of place. I felt I had to have something on the hatch to compliment that.
Also, you are going to want some tips that stick out a bit further as the stock ones get a bit eaten up by the overhang. In order to install the BMS billet tips you have to grind off the 3 spot welds on each stock tip and the BMS tips slide (just barely!) over the mk7.5 raw pipe.