One problem related to ignition switch has been reported for the 2008 Nissan Frontier. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Nissan Frontier based on all problems reported for the 2008 Frontier.
While driving the truck will shut off just like the key was turned off. This happened one or two times a day over a ten day period, I swapped my old key with my wife's key and the problem went away. I took it to a Nissan dealership and they wanted to do $7000 of repairs and nothing about the key and ignition switch problem. So I have been using my wife's key for the past five days and no issues. Nissan claims they never had any problems like this although the internet shows a recall in 2010 for 2003-2006 Frontiers for a very similar problem.