<span dir="auto" style="vertical-align: inherit;"><span dir="auto" style="vertical-align: inherit;">So this is something that's been bugging me ever since I got my 2015 A6 3.0 TDI serviced at a place that I'm not 100% sure I trust anymore. I took it in for a transmission fluid change at about 70,000 kilometers, and the guy assured me they used the correct ZF fluid and followed all the proper procedures, but I've got this nagging doubt in the back of my mind because the car hasn't felt quite right since the service. It's not that anything is obviously wrong, it still shifts reasonably smoothly and there are no warning lights or anything dramatic, but there's just this subtle difference in how the gearbox behaves, almost like the shifts are slightly softer or less precise than they used to be. I've been reading up on it and apparently using the wrong fluid spec can cause all sorts of issues, from increased wear to poor shift quality, and the thing is, I have no way of actually verifying what fluid they used. The invoice just says "transmission fluid" with no part number or specification, and when I called to ask they just said it's the correct one and not to worry. I've heard of people having their gearboxes ruined by places that cut corners and use cheaper, incompatible fluids, and I'm starting to panic that I might be heading down that same road. I've been looking for a specialist that I can trust to check the fluid and possibly do a proper drain and refill if needed, and I've come across a place that's described as a Genuine Audi transmission repair shop in Musaffah Shabiya, which sounds like they'd actually know what they're doing with these ZF units. I guess I'm wondering if anyone else has been in a similar situation where you're not sure if the right fluid was used, and whether it's worth spending money on getting it redone just for peace of mind. I'd also love to know if there's any way to actually test the fluid to confirm the spec, or if I just have to trust the workshop and hope for the best. This is really stressing me out because I love this car and I'd hate to think I've caused damage by trying to maintain it properly.</span></span>