I installed the Gruppe-S UEL headers and overpipe today and wow, it sounds great. at idle, I can barely hear the car but man, the rumbles it gives the higher up the rev range you go... it's great. downshifts also sound extremely nice. I am running an OFT stage 2 tune with the headers. the install went pretty easy aside from having to deal with the pain in the ass stock overpipe. I took off the heat shields on the stock overpipe and it slid out fine after that. probably took me about 4 hours total but I was working on and off on it and had an extra set of hands to help me.
here are some pictures:
a funny moment I had was when I was about to install the heat shield and was reading through the instructions in one hand and had the shield in the other. as I was skimming through the instructions, I read a line that said it is recommended to wear gloves while applying the heat shield otherwise you might cut yourself on the thin aluminum of the shield. as soon as I read that line, the heat shield was in my other hand and I was about to put it down and instantly gave myself a long cut on my palm lol. what perfect timing.