I was told by the copper that defected my Cortina years ago (too low) that suspension was an automatic regency item, as were seatbelts, and other things considered "safety issues" (like wheel spacers etc).
Would be nice if there was clearly spelled out legislation, readily available, so it was easy to find out EXACTLY what was and wasn't ok, so there was no confusion, and maybe some consitency (as it seems everyone wants).