So I'm new here, have had my car for about 1.5 years and have recently started to replace tons of things on my Jetta because previous owner never did. Here are my most current issues

1. Oil pressure light keeps going off: I got an oil job towards the end of October. Since then, my oil pressure light sporadically goes off, usually when I'm slowing down. There is more than enough oil, and the car isnt overheating, so what's the deal?

2. Car alarm: My car alarm constantly goes off for no apparent reason. And it never goes off for a long period of time. It will just go off for thirty seconds, and then stop.

3. Gear lights: In my panel above my steering wheel, all the lights come on when I flick the switch to turn on my lights EXCEPT the light that shows what gear I am in. Is there a special bulb? If so, how do I replace it?

4. Locking mechanism: My driver side lock where I insert the key needs to be replaced, as it is nearly falling off so I cant turn my key in it. Is it better to go to a VW dealer and have them install a new one or can any mechanic do this?

Answers to any or all of these questions would make my life SO much better. Also, if you think some of these things may be interconnected, let me know. Thanks.