2000 w-plate TT failed m.o.t and only on the broken rear springs........problem is they are Eibach springs,i need 2 but is there any way of finding out which ones are fitted to the car,they are black in colour and the only numbers on them are1500 102 i dont know how low these spring are 20,25,30,40mm ???????? id like to replace only the 2 but need to know what they lower by. The m.o.t guy said there genuine springs......i dont think they are as car is pretty low and has 19" rims on it. Eibach 1500 102 is also stamped on the spring. Any cheaper alternative?