Diagnostics have found nothing and our local garage is puzzled. Distinctive flutter or pull back when driving over 40 especially at motorway speeds. Drivable but unnerving when it flutters/jerks a couple of times every few seconds. Filters have been changed and additive put in fuel by garage. Rev counter and speed unaffected. Drive quality not great. Can kick off cruise and skid symbol can show sometimes.

 

My 2005 XC90 has started doing something similar, but the fluttering doesn't seem quite as frequent as yours (happens a few times per month) and my anti skid message is always on now. The mechanic said my ABS Pump needs to be replaced... I'm unclear as to whether this means it is safe to drive.