Does anyone gave thought (or has actual experience) in adding an ADF to the SR20 avoinics.
Yes, we went through this process, and had actually purchased a second-hand KR87 receiver, and were about to get it installed. However the problem was where to put the indicator (there is room in the B model radio stack for the receiver - there may not be in the C model, though).
The place that we had believed we could mount the indicator was in the bolster panel, next to the magneto switch. However a request to Cirrus as to whether the metalwork behind this panel is structural and if we could cut a hole in it got the reply that, yes it is structural, and to determine if a hole could be cut and whether any reinforcing would be required would need us to hire an engineer to do a stress analysis.
At this point we decided against doing it, and the ADF receiver has been resold (I think).
There are lots of new GPS approaches being published in Australia, although they still cannot be used to satisfy alternate requirements, but we are hopeful that this will change in the not-too-distant future.
Hope that helps!