James_

My M5 has a rear shock absorber needing replacing, and given the difficulty of replacing them I will replace the pair. OEM parts are a fortune out here (isn't that right Gordon ) but it's either that or well and truly open my wallet for a coilover kit, probably H&R.

I can source Bilsteins (code BE5-2829-HO) from the US as mentioned in another thread, but these shocks are also listed for other E39 models - shouldn't they be specific to the M5 in terms of valving ?

If I do decide to go with the H&R kit, I've not found much info on here about them. Anyone ?

M540i

There are several options that may work for you, but you really have to look at the style of driving that you are doing. Is the vehicle a daily driver and on occasion you feel compelled to get "sporting" with it and actually put it through its paces in a spirited type of drive? Is it going to be tracked frequently? Or is it more of a weekend driver where it's spirited driving only?

With the daily driver only, you can probably get away with doing a nice set of shocks and struts and a set of springs with a firmer spring rate. My recommendation is going to be towards Bilstein Sport shocks and struts and H&R Sport springs. I guess I may be a little biased, but the Bilstein PSS9 coilover kit looks very nice and any experience that I have personally had with anything Bilstein is that they are all overbuilt and will generally outlast most other manufacturers without the need for revalving.

There are a number of excellent choices available out there. Ground Control makes a nice set-up. KW makes a nice kit for the M5 as well. Koni makes some nice shock absorbers. The general consensus with Koni though is initially they are nice and firm, but before you even put any significant amount of mileage on them, you feel like they are floating through corners and rebound rate is been diminished a little bit.

All of these items can be sourced from any of the board sponsors. Like I said and like you will hear from many of our other board members regarding this subject, it really depends on what you are doing for driving. I equate suspension set-up to the Goldilox and the Three Bears theory; somebody's too hard or too soft could be someone else's "just right". So it's very much about preference. Do your research and do your homework. If you know anyone with an M5 with an aftermarket setup on it, ask them to go for a ride and see whether or not you like it because you are looking at changing out your existing factory suspension in favor of something "better".