SAAB 9-5 Wagon HK Sub-woofer assembly. 

These units are generally reliable when used at conservative volume levels.  However, frequent use at HIGH volume tends to cause foam failure from the expensive dual voice coil sub-woofer unit.  Saab used an amp that is capable of driving these units close to their maximum wattage rating, which will cause failure if used for prolonged periods.  You will hear this failure because the speaker cone is no longer supported and will scrape as it runs in and out of the unit.  The speaker will sound horrible once the foam has had a total failure.  I warranty these units against DOA only.  I have tested this.  It worked for me. Once YOU install this, you confirm it works, you own it.  I will not accept a return a week or a month or a year later.

This unit was removed from an older gentleman's car which was recently taken out of service due to sludge... and I don't think he often listened to "the rap music" - so this unit is in super shape, as you don't get much of that from the news radio stations in Philadelphia...  Foam is like new, unit functions perfectly.  You should get a lot of life out of this!