I just slapped on yellows with hr springs. It definitely firmed up the ride. Bumpy roads still suck. Im sure its because its lowered and it dont have enough travel. Unless you get really expensive coilovers the ride will suck. If you want plush with yellows get springs that will not lower more than 1”. Or keep the oem springs on.

 

It is the nature of the beast.
The standard E46 M3 is stiffer riding than the E36 M3.
For Bad condition roads with no track go OEM springs with Koni sport or Sachs/OEm dampers.
Anything else is probably not money well spent.
The money left over from ignoring the coil overs could go towards refershing the suspension.
Your suspension will need attention if you're still running the original dampers.
A suspension refresh will also do more to eliminate driver fatigue than the coilover kit and the extra NVH that it may/may nit induce.
The worn out suspension bushings probably causes most of the driver fatigue.

 

I was facing the same situation and did a significant amount of reasearch. I ended going with the Koni Sports with stock springs and am happy with this setup. I don't think that you can get much more comfortable than this without radically changing the nature of the car. I just drove my wifes 2003 325 for about 800 miles and honestly did not think it was more comfortabel than my M3 setup. It just does not control body movement as well. Yes to the comment about refreshing your suspension. Replacing my drop links made quite a difference. Look at these two threads and you may find them helpful.
(6) Coil overs for comfort | Page 2 | E46 Fanatics Forum
(6) Vert harsh ride resolved | E46 Fanatics Forum

 

get the Koni Sports and the TC Kline Koni Sport adjustable rears. I like H&R over Eibach but the Eibach pretty sure is a slightly softer ride. get either in their street “progressive rate” spring not the linear for your roads imho.

i’ve run Koni Sports over three decades on my cars. I like them. I do however like the Bilstein PSS10 for a street coil over(on last two E46s). but honestly it’s probably more than you’ll needed for your use.

 

get the Koni Sports and the TC Kline Koni Sport adjustable rears. I like H&R over Eibach but the Eibach pretty sure is a slightly softer ride. get either in their street “progressive rate” spring not the linear for your roads imho.

i’ve run Koni Sports over three decades on my cars. I like them. I do however like the Bilstein PSS10 for a street coil over(on last two E46s). but honestly it’s probably more than you’ll needed for your use.

Single adjustable?

 

Get the koni shocks and H&R springs from FCP EURO. Lifetime warranty even with wearable items. You can refresh the suspension from the crappy roads every few years. I don't think the Koni and H&R warranties will cover regular wear and tear.