So when I got my car I noticed that the car started up/shut down roughly. The last two weekends had to jump start the car even though nothing had changed. So I went to look at the battery to see if it was dead. It was completely dry.

I looked from the side and realized there was no shading through the translucent plastic. So I went to the store, got some distilled water and filled each cell too full. BTW, it was completely dry, must've used 1/4 - 1/3 of the gallon to fill the whole battery.

After jumping it again and driving around, when I went to shut it down it was instant. No shuddering at all.

I'm beginning to suspect that some of the startup/shut down shudders might have to do with a weak/dying battery. Hope this helps someone.