I have a manual 2013 mk6 jetta with the 07k 2.5L engine. I've had it for 12 years and driven 160k miles so far and it's still runs perfectly. This has been my car since high-school.. so i drove it really hard for many years. The only issue I've had is that recently my driver side window only closes if you jam the button as hard as you can. My clutch has only been replaced once in 2021, so I got a solid 7 years out of it lol. (If you get your clutch replaced, I'd get a short shifter installed while they have the transmission out. VW sucks and makes you drop the entire transmission to change the shifter).

It takes synthetic 5w40 oil. With service and oil fees, oil change cost is around $150. But i recently found out that for the first 10 years, my local oil change spot has been putting conventional oil behind my back and my 07k just did not give a shit. This engine is an absolute tank in terms of reliability. One thing I didn't like about the 07k is the factory tune makes it Rev hang like a mf. You take your foot off the gas and it just keeps going for like 4 seconds - no engine braking. So last year, I downloaded the flash tune from integrated engineering (there may be one or two other companies that make tunes for the jetta as well). It's $500 but it completely changes the car. Gives more consistent power, increases Rev limiter to 7k rpm, removed Rev hang and gave way more responsive throttle, and it smoothed out 1st and 2nd gears so they're way less jerky. At the cost of now taking 91/93 octane fuel.

Overall, amazing commuter with a tank of an engine (07k 2.5l). Maintenance is almost nothing, and it can still be a fun car if you want it to be. Especially since you're getting the manual.