Basically I've killed a VAG rear wishbone bush in 7K miles.

Plus my mum was driving for a lot of those miles and a lot were motorway miles, however admitedly I do a lot of late night driving and reasonably hard.
The wishbone is sitting over the bush, it's not really even connected.
The car isn't even that low, sure the wishbones do sit upwards a little, but not as much as they sit downwards as standard if you get me.
When I put them on I left all the bolts lose, drove up a bumpy road put it on the ramp so it all sat naturally and did them up, so that the bushes don't get too twisted as the ramp is let down.
One side is alright still but the other is knackered. MOT man reckons poly bushes. Would these be more suspect to "levering out" as Mr MOT put it?
Or should I just get some TT bushes?
Like I said the car isn't that low, it's just the rear bush, it's knackered.