Any idea how to fix these issues with springs flopping around or why they are happening? [closed]

So I've made a car chassis using springs as the suspension, but I'm getting two issue to do with the springs being floppy.

This sounds a bit stupid at first and could mean anything, so just take a look at this instead:

Issue Part 1

Issue Part 2

As you can see, this mainly comes in to play when using the handbrake and when the car lands from a height. (The handbrake works via activating limits enabled and restricting the lower and upper angle to 0).

I've tried increasing the stiffness of the springs, but there isn't any noticeable differences as from what I've seen.

If anyone has any idea why this is happening or how they can help, I'd highly appreciate it.

Sidenote: I thought this might be a little off topic for this website, but I only realised I need to actually apply to post on the Dev Forums just now, so I don't really have any other place to post this question, as far as I'm aware.