While the 07K is known for his outstanding reliability, there are still a few minors issues you might encounter. Don't worry though, they are relatively cheap and easy to fix!
Leaking vacuum pump
Located right above the transmission, the gasket on the pump tends to fail and leak oil all over the transmission. You can easily confuse a leaking pump with a failed crankshaft seal.
The general consensus about fixing this issues is to simply delete the pump by using a block-off plate. This fix will make use of the engine vacuum to supply the brake booster instead of the pump. This configuration offer no drawback compared to the OEM setup.
For a list of brands who sells block-off plate, please consult: Aftermarket Parts
There are also companies who sell kit to replace the worn gasket, this avoid the need to get a new pump and it's cheap.
For peace of mind, we would recommend removing the pump
With time, they start hating water
Knock sensors use a sensitive piezoelectric crystal that generate voltage when it vibrates. They monitor knock / noise and report it back to the ECU so it can adjust the ignition advance accordingly
With wear, water and even humidity can affect the sensor ouput and set the engine in limp mode (EPC light might or might not turn on)
Located under the exhaust manifold, it will take less than an hour to replace them both.
Do not cheap out, if one fail, the other will possibly fail sooner than later.
Leaking PCV diaphragm
The PCV diaphragm is located directly into the valve cover. It opens and close gradually according to the intake manifold vacuum, it vents the excessive crankcase pressure build-up into the engine. The diaphragm tears causing a vacuum leak thus resulting in a rough idle.
Remove the oil cap, if there is vacuum holding the cap down, the PCV is bad.
Dorman sell a repair kit for about 20$.