From the article:
Up for auction is this extremely rare and unique 1999 Cadillac Eldorado owned by the late Clarence Clemons, saxophonist of Bruce Springsteen’s E Street Band. The car is only 1 of 5 “TwinStar” models built by Mosler Engineering in 2000 with an additional NorthStar V8 engine in the trunk powering the rear wheels. The result is a combined 575HP and 4-wheel drive.
Photos and article - 16 Cylinder AWD Cadillac Eldorado by Moslerby Mosler