Others have asked this same question on other Kia model forums, specifically Cee'd and Sedona. My Gentex mirror arrived last Friday, which included a camlock adapter because I didn't know the type of mount used by Kia. I now know and thought it would be helpful to share this information with other users. On the 2G Sportages (and many other pre-2010 models) Kia used a rear view mirro mounting system specific to Kia/Hyundai only. The mirror is held in place by a retension spring only, no locking screws or tabs. To remove the mirror from the mount, pull DOWN on the mirror forcefully while wiggling back and forth. Eventually it will come out. The bad news is no one makes an adapter for this mount. To use a Gentex mirror, a standard wedge mount must be glued to the windshield. The new mount can be placed below the Kia mount, but there must be enough room between them to slide the new mirror on over the new mount (the mirror slides down over the top on a wedge mount, up from the bottom on a Kia mount). I decided to remove the Kia mount, a fairly easy job using the cutting blade on my reciprocating multi-tool. After removing all remaining adhesive, I glued the wedge mount in place just below the Kia mount location. Some extra work, but the finished product looks clean and professional.
Hope this information may help those wanting to upgrade their rear view mirror.