Did some digging around and found other drivers had some issues in regard to this. Not just WK2's but other jeep platforms including some dodge vehicles. Seems when ever I take a turn, hue driver seat squeaks more than granny's old rocking chair. Really annoying. Some say it has to do with the lumbar support, but I don't want to go to the dealer with out some input. Tried adjusting the seat worked well in some ways but eventually led back to the original issue. Seems there's an issue with the support of the driver in the seat. But again I don't know ....
I had the same issue a long time ago...the solution was wasy..just move the seat a very little bit forward or backwards and that did the trick, for whatever reason in the position it was it made a squeak, after almost going nuts try to find out what was causing the noise I tried the above and never heard a sound again.
Hope that helps, try it.
Rgds.