My polo as started having problems with acceleration...I'll go into 3rd, then the speed goes down to what feels like 30mph but the revs stay, the only way I can get it going is either going into a lower gear or taking my foot off and back on to the accelerator. Even when going into a lower gear after a few seconds it will do it, there will be about a minute or two of driving where it won't happen and then it will kick back in. I've had this happen a while back and it only lasted a few days then the car was driving normally, we put it down to the clutch. As time has gone on and it's kicked back in it feels like it is getting worse, even when trying to pull off in 1st gear it pulls back and slugs along and then starts juddering as if it's about to stall so I have to whack it in 2nd to drive normally, at this rate we can only guess it's the gearbox and others reckon it is too, but it's hard to explain what is happening unless you are driving it. It will sometimes just jolt and carry on as normal for a moment if keeping my foot down, but this feels like an ongoing issue and a scary one in fact, it's happening in 5th as well as every other gear too. It happens on whatever road wherever, it will always kick in going up little ramps in the road and I've tried everything I can to test it out, driving in higher gears and lower, going certain speeds (it doesn't actually happen much around 5/10mph...) and if anything driving normally? we are stumped. Would anyone have an idea?