'04 545i... is the trunk supposed to spring up fast and slow just before it's fully opened or is it supposed to be a soft open all the way?
What's normal operation?

 

There is a DIY to help you with this question. In addition to the lid being spring loaded to pop up there is a small pneumatic-type shock absorber to slow the pop-up and prevent the lid from smacking someone in the face (if they're standing near and over the trunk lid). I seem to recall the shock gizmo was not present on some early e60's but can be added easily. And the spring tension is also adjustable - search for add'l information in this forum.

Here ya go >>> https://5series.net/forums/e60-discu...sively-109420/