I've seen a few threads on this, and I've bought some McGard locking wheel nuts, model 24157SU. I have an IS200 Sport with the OEM alloys.

Several people seem to have reported using these nuts, but they look completely wrong to me. They have a cone-shaped seat which won't fit down the recess in the wheel where the bolt goes.

The guide in Halfords is very unhelpful and confusing, but the one on the McGard website here seems to be pointing to model 21156, which does look at least right in the picture (i.e. flat seat rather than cone).

I wonder if there's any difference in IS200 models ? Mine's an early one, 1999.

Can anyone shed any light on this ?

I finally got around to fitting these, and the 21156 McGard nuts seem to be the correct ones, they fit fine.

I'm sure that 24157, as I've seen some report using on here, are the wrong ones