So like it says in the title, the car/steering wheel kind of vibrates when I have the wheels all the way to the left or right. It doesn't do it in normal turns or when driving straight, only when parking or backing out. Any ideas?

 

Most likely you are feeling the pressure relief valve working. It is bad practice to turn the steering wheel full lock and hold it there. Very high pressure builds up and the relief valve releases the pressure to keep things like hoses and seals from breaking.

 

Well I dont try to hold it full lock but when I need to park or make a narrow turn the steering wheel must turn full lock sometimes.