H&R Sport Springs
Here at MPT we know quality. When we look for parts to offer, and we are looking for suspension specifically, H&R is easily a go-to company. We recommend their coilovers, shocks/struts, springs, and other suspension bits for the best reviewed handing and ride quality at their price level. H&R chose specially sourced 54SiCr6 spring steel with a rated-strength of 290,000psi to give an end-result of high-tensile strength, durability, and long-lasting performance to these springs.
If you're seeking the best trade-off between ride-quality, performance, and aggressive looks, then this is the set of springs you are looking for. The 2005 Ford Mustang will benefit from a lower center of gravity, reduced body roll, and better handling. Superb ride quality and comfort can be had with proper alignment, especially when paired with a good set of shocks/struts.