The coilovers on the rear aren't coilovers anyway, so the car will still be on normal springs 
Sorry if I seem stupid again, but I did not really get this bit...?
I'm hardly an expert in the field, but I'll try to make sense of it...
Usually on a coilover kit, the spring is fitted on the damper, and is usually adjustable for height. On the A500 there isn't the space for this type of system on the back, so the spring has to sit seperate from the damper and in the standard spring pockets. This also means the rear ride height connot be changed without changing to different springs, unlike the fronts which would be changable simply by winding the spring collars on the dampers. If you google some images it should all make sense
