Maybe you're not looking closely enough. The wires are very thin. Also, if you're accustomed to the inch-apart spacing on most American or Japanese cars, the wires in the W126 rear window are only about 5 mm apart. Yours may be all working (I have a dead strip an inch or two wide) so you probably won't see any kind of lines. Are you getting any defrosting action? My guess is that it's working so fast you won't see any of the defroster lines.
Lehigh Valley PA USA
73 Olds 88, 72 MB 280SE, 78 Datsun 280Z, 71 T-Bird, 72 Olds 88, 83 Nissan Sentra, 85 Sentra, 73 230.6, 91 Integra, 83 300SD, 91 Volvo 940GLE wagon, 84 300SD, 95 Subaru Legacy L wagon, 02 Mountaineer, 91 300TE, 08 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon all gone... currently
2007 Honda Odyssey Touring, 2011 Honda Odyssey Touring