Whilst having a look at front geometry (too much negative camber, which causes it to tramline/bumpsteer a lot) and fitting new Lotus spec top mount washers to stiffen it up a bit, it was also pointed out that the idler arm 9095731 had a lot of play in it. When we got it off, it looks ok so it must be that the rubber bush has gone soft. Of course a new part is NLS, so I ordered a Mevotech one (MS50901) on Thursday from Rock Auto (Cadillac Catera part) and it arrived at 12.30 on Monday £67 landed total. In fact from the Rock Auto site also listed a Lemforder alternative (1492701), and it turns out they are available from Nottingham for £58
. New one is now fitted and seems better than the old one in terms of vertical play, which should help the bumpsteer. Now just waiting for new front discs and pads and I'll be able to give it a try.