Coupe and Sedan Suspensions Same?

Tanabe's website says they are same... Tein says they arent... H&R says they are the same... What is the truth? I want to drop my sedan 1.5ish all around with some lowering springs... who should I go with?

coupe springs make sedans sag in the rear

neuspeed has specific springs for a sedan

sedans have harder spring rates in the back because they are heavier in the back. (more junk in the trunk 8) ). So buy a spring set specific for sedans, or coilovers.