OBX headers are fine in comparsion to BBKs. Had a set for awhile on my old S197 V6 for a stint. Fitment was fine, quality was good too. If I remember correctly you will need O2 sensor extentions unless they come with them. Someone can chime in that has had a set of LTH installed on the S550 chassis about the wires. I can't remember if some had enough play on the S550 and could unravel the stock wiring and they worked fine without extensions.? As far as inspections go...well, that would depend on the inspector and laws in your region. The minute you delete your stock cats, no matter if you replace them with aftermarket hi-flow cats, you are automatically gonna be voided on a full car inspection. However, some places may not do an actual eye inspection of the exhaust and do the sensor on the tailpipe and test for just emissions. Heck, or you find the place everyone just pays a little extra money to pass lol. Again, not sure about laws in your location.