Guitarmageddon- Sorry, but not surprised, to hear it didn`t go better. Regulars here know that I`m pretty fanatical about preserving clearcoat thickness, but this is just so similar to what I`ve gone through (i.e., I had to *hammer* "light holograms" with M105 for the first step) that I still think I would`ve just used something more aggressive after the first few tries on the test-spot didn`t work.
I *am* assuming that you worked the test-spot with varying combos until it got OK. If it never did get OK then something`s wrong and you gotta reassess. On a hard clearcoat *that I had no reason to suspect is very thin* by the third combo I`d be using something
I sure wouldn`t wetsand it as the sanding scratches are gonna be *more severe* than the current problem. Don`t try to resolve marring by instilling *more and worse* marring

Well...OK, maybe there`d be a net gain with 4K but unless you`re *VERY* experienced with wetsanding *that particular paint* I`d still rather just use something like M101 (NON-diminishing abrasive so you can stop at the exact point that the problem is resolved rather than working through the breakdown-cycle) on a MF Cutting Disk and then clear up the micromarring from that with a Finishing Polish (again, I`d use a NON-diminishing abrasive for the same reason) on a regular polishing pad.
Eh, I guess I keep returning to solutions that involve buying different products from what you currently have, but it doesn`t sound like you`re all that satisfied with how things are going.
Oh, and..heh heh, I`d try to purge your memory of those "one pass success stories" as this Jetta is a whole `nother ballgame.