Also, how would I be able to access all the information about, every detail of the parts of my 2011 vw gti?

Like it losing pressure, i changed thermostat, and water pump, yet still acts funny. Fyi. I blew fusees while touching wrong battery post

Car never gets really warm anymore unless I have the defrost on in winter temps. Blows warm on driver's side. Same with the air...it never really gets cool enough in the summer time.

When I run the defrost and/heater there is no hot air coming out. If I sit idol the thermostats (idiot light climbs to hot) quickly. Neither defrost or heater worked this morning.

Fuel did not go through when i add fuel from the gas station,

After i changed alternator

trunk release quit and shifter gets stuck whenever it feels like it not always might do it for a week then again month or two later

So I went ahead and replaced the alternator and the light went off. The next morning it came on again. I also have an issue with one of my brake bulbs. I noticed that every time my battery light came on, so did the brake light. It did this about 5 times and then it stopped. I also noticed when the battery light would come on my car ran smoother, when it went off it went back to running rough like it usually does. I checked my battery and its fine. Totally stumped. Need help!!!!

Is the check engine light on for the examples given? My check engine light is not on, I have no issues with the shift changes (I have an automatic) and just had an oil change and service done on the coolant system. I put the gas cleaner in my gas tank and re fueled. The crackling noise I was hearing is not as loud but still hear it a little. Not sure what it is. I happens when I accelerate the car while driving.

none needed