Sequential shifting transaxles have the convenience of being easily adapted to both mid-engine and rear engine cars. Here you can see the shift linkage connections, easy to run either direction, front or back.
One of the nice features of the S4 is the ability to upgrade existing MD4 transaxles with the S4. It uses has identical mounting locations as the MD4. The only area you’ll need to check out is the transmission height, which is about 2 inches higher. The differential area of the transaxle (the middle area above the CV flanges) is the same height.