What does ASC stands for on a BMW z3 1997?

The Z3 97 has a thermo housing, its right in front of he fan and if you change it you need to drain the anti-freeze and when you r done replace it with BMW Antifreeze, add 50 water...cost 20.00.....

There is no air conditioner filter in a Z3.

under bonnet/ hood they are in a black plastic case to the rear right.

That's a tough one. The 528i weighs less, but has an engine with less torque and horsepower. Honestly none of those cars are exactly "fast." How about this, a 1997 540i has the same engine as a 1997...

There is no cabin air filter in a Z3.