I've just checked the new VW Group ones for the Polo/
Ibiza/Fabia/A1 and they are TX30 - and, when I checked my Draper bit set, the only bit that has been broken is the TX30 - so probably back in January 2006 it would have been the 2002 Polo drop link that caused that!
So that left a bit set with one very short but still usable, TX30 bit damaged, I gambled on Laser Tools bit set using the same "hex size" and as they sell spare bits, I bought one, so that slot got filled with a new bit. I might use that broken bit again for holding a drop link "end" not much more can happen to that one, if it broke again, I'd be able to bin it or grind it down and use it for "knocking things out!.
The aftermarket TRW pair I bought a few years ago are 5mm hex, so any possible "type" has been is still is being tried.