Finally! I feel useful for something here besides annoying questions! I can provide help for a change! I use to work on them for a living at the dealer before I went to BMW. I have owned nothing but for my dailies, great cars. My wifes 06 Jetta has been to the dealer once in the four years we've owned it for peeling radio buttons. My 06 GLI has been more fun, it has the DSG gear box with twin clutches, direct injection and a turbo, but I monkey with it but it has been a good car too. The exception would be the 99.5-04.5 MK4 Jetta/Golf. They are still good cars, but have their issues. They love their check engine lights and airbag lights they can be a little more maintenance intensive, but they are a stop gap between a civic and a BMW, great fit and finish, great performance and safety. If you have a 1.8T T-Belt AND water pump MUST be done every 60K. Not 61K, or 60,500. They snap and you are in for a cylinder head.
I would have to pull the faults out of it to be more accurate then an internet diagnosis. If you can get the faults read that would help. Check the VW boards like VWvortex.com guys there can read it out. I would since I have the VAGCOM but wrong side of the country. One thing to check is pull the connector on the coolant bottle for the level sensor. The bottles can go pad, leak coolant INTO the wiring harness and it will seep to the ECU and instrument cluster. This was common on the Jetta/Beetle/Golf. ECU/Fuel pump relays also give a lot of problems.
Feel free to PM me if you need some pointers or help. Any of you. You guys have helped me with my K5 and first domestic, its the least I can do!