Is this the same as ARS? Or a different system? How do you know if you have it?

 

ARS = Active Roll Stabilization.
Quick way to check is to look at the rear stabilizer bar from the rear of the car. If it has some sort of motor in the middle of the bar you have ARS.

I'm pretty sure only the E61 wagons have the self leveling suspension.

 

Self levelling is not the same as ARS, it is used on the Tourer E61 to raise the rear end as weight is added as Tourers tend to carry heavier loads.

it does detract from the handling somewhat, the tourer is not as agile as the Sedan.

 

Ahh ok I was seeing that the h&r springs on tire rack had a closeout sale for the springs that go with the self leveling optioned cars for $141 for 4 corners....thought I could grab them but I guess not.