I am trying to remember the names of the couple who disappeared in their car, and were later found in a swamp or a lake or something...anyone remember?

Unless I missed my guess, I would say that it was Bill Rundle and Traci Kenley. UM featured the case in 2001, just one year after they disappeared. Their remains and the jeep they were in were found in a drainage pit. Dental records were used to confirm the identities. Their deaths appeared to have been accidental. :(

http://www.wowt.com/news/headlines/52727.html