First time I took it on a road trip (400 miles length) it blew a cylinder. Towed 85 miles over mountain range to nearest dealership, took week and a half for them to rebuild, cost me $2000, plus being stuck out of town for so long. Mileage on the car was under 100k, so it would have been covered for the original owner, but VW cuts the warranty down to 50k for subsequent owners.
Aside from the expected wear and tear (2 new sets of tires, 3rd battery, and new brakes) I've got the common Jetta owner problems:
Door moldings fall off (just did the third reattachment)
Air bag light on for last few years, intermittent.
Dash light for window defogger intermittently on and off.
Alarm usually goes off if you try to unlock & open just the trunk (again, intermittent,) so I have to unlock the door first, to deactivate the alarm.
Driver door lock not working well. Looks like those commonly go out.
Fabric on front edge of headliner dropped and is hanging there. Shop tried twice to re-glue, but the headliner edge is rotting from sun, so it won't stay attached. I've since stuck a row of straight sewing pins into the foam to tack it up there.
Inside light intermittently will turn itself on, even when the car is parked and locked, and stay on for days. I can no longer trust it in the neutral position (which is supposed to just turn on when you open the door,) so I have to keep it off always. Hopefully muggers won't be lurking in the back some night when I unlock my dark car.
Dipstick tube snapped when I was checking the oil, so I had to tape the dipstick in to maintain pressure until I could get it seen by my mechanic. (Of course I was out of town, over a holiday.)
Cruise control out since 2003. Mechanic has spent some time changing hoses but has yet to find the exact cause.
Got this from the dealership as a two-year old high mileage lease return. I've only put 43,000 on in my 9 years of ownership, which makes it pretty high maintenance for the dollars to miles ratio. I have the oil changed and car looked over by a VW only mechanic twice a year, which is about ever 2000-3000 miles.
Best feature is the huge trunk. Well designed, with the hinges out of the way so you can fill it with big stuff.
Cup holder is annoyingly small. Good for a 12 ounce soda can and not much more.
My third VW, and possibly the last. It just hasn't held up as well as earlier VW's I've owned.