thanks I know I could go to any off the street, was wanting the kit to fit the Audi with the least amount of effort. i.e. the rear lower black section is simply clipped on; remove this and clip the new one in place; genuine Audi parts are preferred as it is purely cosmetic don't see how it could void any warranty other than maybe the paint corrosion warranty not worth the paper it is written on. The main exhaust itself would be unchanged the extra tips are cosmetic only from I have seen on some/most kits. Wouldn't want the s/s full systems as don't see the point and the tips when moved away from Audi's OEM just look boy racer, they miss the panache of OEM kit. and for any haters out there if I wanted a £1000 a month fuel bill yes I could have purchased the S4/RS4 but I am Yorkshire man...and if we all drove the same car we wouldn't be here in a owners forum helping each other out. Sorry in a mood today loads of keyboard warriors at work so again sorry if that came across wrongly...Best I have seen so far is this
http://www.ebay.co.uk/itm/Rear-Diffuser-Lip-Bumper-Skid-End-Pipe-S4-Style-For-Audi-A4-B9-2016-2017-Sedan/182525918183?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649
but a lot of kits state NOT for the s line as the s line has a different fitting to ANY other model in the range...yep the SE and sport models have the same fittings as the S4/RS4 from what I have found out so far...