Off my car.
I've fitted longer, softer springs. These are probably best suited to people who spend more time on track than I do, they're firm but not back-breaking on the road.
£20 plus P&P? That's about half what a new set would cost.
I'm based in Cardiff, but work in St Albans, so I can meet you on the M4 corridor between those two or at my office or home. Whatever suits.