No unfortunately none are compatible and require a full bumper change. There are knock-off ones that will work with your existing depending if you have sline or non version of the car. Check AliExpress or eBay.
Maybe I should have added some context, but thanks for replying.
I have an A3 5 door sportback with an S3/S-line rear bumper already installed. However, as I am moving to a duplex exhaust, I need the S3 diffuser, which I also have in the basement. But, the diffuser came from an S3 3 door hatchback, and not a 5 door hatchback (sportback) like mine. Picture is of my car.
Its a good question and I dont know anyone whos done a job. I myself have a sportback and got hold of a 3 door bumper and realised they are not the same shape so I tell others of my experience. As for the diffuser, I guess you wont know without trying to fit them. If you know how to take the bumper off and have the time then worth giving it a shot and report back
I did the conversion from non sline to s line bumper but the diffuser on my 2nd hand bumper was in terrible condition. I thought I'll get a good 2nd hand sline diffuser cheap and it it on before I had the car to the garage to do some other jobs but noticed pulling off the diffuser is a lot harder without braking any clips.
All in all I think its a rear off bumper job and to look at the clips carefully to know what your dealing with.
if you do know of a way to remove the diffuser please share with us as I'm interested to put a Rieger on mine down the line (non dual exhaust tip version)
Well, the diffuser I got came attached to a S3 3 door bumper, where I removed the diffuser from. Agreed, it’s a bit of a fiddle as the “hooks” are WAY bigger than the actual holes, but I got it detached after about 15 min. using a small flat screwdriver and taking it one hook at a time. Small damage was done to the bumper in the holes from the screwdriver, but nothing major.
Part numbers will vary from one country to another. If you look at ElsaWin they can have different (usually last later has some kind of meaning....maybe???)
What I usually do to help identify those pieces is look on ebay for the item, the seller usually has a close up photo of the part number (if not I ask the seller to send this info across to me) and then once I gather those 'part numbers' I google them and make a judgement which one is suitable for my car / country.