please dont fit coils i have driven a few with coils they all felt like a ship on high seas you would get sick in them and they never seem to look correct too high on the back when empty and put a heavy trailer on it sits down. look after your air suspension get it taken care of properly once and you should have no more problems as it probally never got much attention up to now it might cost more than the coils to do but you will have a much better machine dont mess about with the air suspension yourself as wammers said there is more pressure side to side and front to back . if you are willing to spend a few pounds on your machine once in a while you will have a good one . i have a 95 dse with 249000 miles on it with no oil leaks not one rattle or sqeak starting first tip hot and cold but i have rebuilt the brakes (hoses metal pipes callipers discs pads )the cooling has been done rad, stat, water pump, and viscus also done all the bushings pipes etc. if you dont spend on a vehicle you wont have it long . you will get great advice here but the quick fix is the most expensive