hmm, in that order? I thought you were married?
ZF for surrree I assume they are easier/cheaper to find.
* edit * so i replaced the air filter in my hatch with a standard Mann one. Now the B48 doses slightly... I'm getting bad ideas.
Amps probably stuffed, might be a blown capacitor or three. So weird with that wiring setup, I'm surprised it worked haha.
Just get a Class D or mono amp (rated higher than the RMS of the subs, check impedance), save yourself the hassle.