Interesting find.
I checked with my official TIS version that sits in ISTA-D. That is from 22-11-2014 (ver. 3.46) so quite old already (for ISTA terms, the old tis was from 2007). That version also has this page already albeit slightly different. These is no distance listed for D (here D=5mm), but you can read the 5mm on the picture with the caliper.
I first mentioned the method here on 19th of june 2015:
https://z4-forum.com/forum/viewtopic.ph ... 3#p1153983 ; by then lots of people in DLD/NL had done this mod.
On the german z forum they first started experimenting with it and reporting it around may 2014:
http://www.zroadster.com/forum/index.php?threads/aktion-problemlenkung.59821/page-75#post-1943088
It never came up in me to look it up in the new TIS because the old one obviously never mentioned it.
Maybe the new tis has more answers to other previously not displayed/solved problems.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch