I'm sure this must have been asked before but cannot find. Had my 2010 RRS since Dec. Has been surprisingly brilliant in this time, sadly on a drive from Kent to Mid Wales a week ago the car started playing up. At around 70mph the engine would momentarily lose power, feeling like it had hit a speed-bump! Would only last a few seconds but happened repeatedly. Thought initially it was a fuel blockage but seems more like a gearbox problem. Tried in different gears at different speeds (above 55ish as was on the M1) and problem persisted. Did not occur under hard acceleration. Tried stopping and letting the car settle but happened again. After 10 mins stopped happening and did not occur again for about a week. Thinking I'd got away with it drive to the coast BH Mon and it happened again. Only happens at motorway speed!? Thinking may need a gearbox flush or could be transfer box related. Car has done 79k miles........any experience of this!? Range Rover Sport HSE and for a bit of weekend fun a S1 Lotus Elise with a few track biased additions!