The license plate lights may not work due to corrosion caused by water intrusion into the light assembly. Cleaning the corrosion and resealing the lamps to prevent water entry should correct this concern.Google+
Car Problem Reports
Saab 9-3 The License Plate Lights May Not Work Due to Water Intrusion
Saab 9-3 Problem
Visitor, 2007 Saab 9-3, 95,000 mi
License lamps full of moisture. Bulb tabs corroded. Bought used lamps on eBay and sales with clear RTV. Had this happen on my other z9-3 as well.