Hi All, Just in case its of use to people. THe original coil springs are hard to find, but are still available from the main Chrysler Dealer as it has to come from Italy. The cost is 124.63 + VAT per side!!!! Generally 1 hours labour to change each side too. As mentioned best to replace them as a pair. The part number is 50709043. The other option is as L Plates recommended and the Eibach pro springs but this requires a change across all 4 and lowers the car so depends if thats what you want. you just have the additional 1 hour labour for both rear springs. My mechanic recommended against lowering if possible, but he says a lot of coil failures happening so one to look out for as the original part is expensive!!!