.........I took your post into consideration, but chose not to respond. The problem with your post is you educated me on the cons of installing springs but then you followed them with unecessary comments. It's like a teacher telling a student "No! No! No! This is the way you do it, stupid!" I appreciate your advice and info in the beginning of your post, but it needed to end right there. Thanks.
You were obsessed with the cost of a pair of springs & the labor charge to install them, down to the dollar. This immediately set off an alarm in my head because I've seen it 100 times before and it's a strategy for failure that's many folks follow.
I decided to institute some shock treatment
by providing strong reasoning, example and embarrassing analogy to help you put things into perspective.
Docile, passive recommmendations to spend 2x for parts generally do not get much consideration.
My posts are hardly similar to school teacher red pen "I'm right, you're wrong" feedback. I provide technical detail, example and insight about WHY dampers, bearing turntables and spring cushions/insulators need to be changed. The camaro and taurus comments serve to put these expenditures into perspective. You should not be using similar pennypinch service and upgrade strategies on an M5 that's worth 50x...but you are.
Honestly, I would much rather you be offended by my post than watch you take a glidepath that leads to bad results or redoing the job, spending double labor and double hassle.
If you now fully appreciate the need to inspect and carefully consider changing ancillary hardware, I've met my objective. If this has not sunken in or you are now totally ignoring me, well, I tried.
For used M5 cars with over 50K miles, a proper spring upgrade will cost over $1K because the weak dampers and spring/turntable hardware all needs replaced. As you can see, it is difficult to get this point across lol.