In this modification of Sorento producer installed W2.1x9.5d type of bulb base. These lights in 2006 model year cars with G6CU motor code show the index at night. Kia installed in vehicles with motor 2.5 tiny lamps for this purpose. Only 5 W of capacity is needed, but the voltage still stays at 12 V. One more thing - Kia Sorento 2.5 needs only high quality optical devices. According to law, you should ensure for Kia Sorento normal work of light over license plate.
If there are problems with 2006 Kia Sorento in index plate light, go to the service. Some experience and instruments are vital for 3.3 engine vehicles with motor number G6DB. If you install more than 5 W and other than 12 V voltage bulb, there will be some troubles. You might have problems with Kia Sorento during installing lamps. Be careful at changing W2.1x9.5D base lamps in Kia cars by yourself.