2004 Jetta Wagon engine shakes and studders, getting worse

About 95,000 miles on odo. Started off as intermittent but now it's all of the time. Feels kind of like it's gulping for air or some such thing. Engine shakes badly, helps a bit when I downshift and run higher RPMs, like 3500 or so. Even at idle engine is rough.

Before I hand it over to the shop to vacuum my bank account into theirs I thought I'd get some community feedback on possible causes.

Thanks.

Bump

Lot's of views but no comments, ideas?

How long since you changed the fuel filter? Might be starved for fuel.
If you recently filled at a new to you station you might have got a bad fill that clogged the fuel filter.
How long since you changed the engine air filter? Same for air.
Have you cleaned the intake? Might be clogged.
Have you added an additive to get rid of any possible water in the fuel? Something like Power Service grey bottle works well.

If you have VCDS, a scan would be helpful.

Check cam for wear.

A 2004 Jetta wagon would not be a MKV think that is a MK4 so you may want to try that forum. Not sure what engine is in that a PD? Also Tranny will be something else I would think.