Not available on DVD at this time.
 
Current information about the release status.
 
 
Downloads of season 4 are available from the following services:
 
Amazon Instant Video:
For people with a U.S. IP address, a residential address in the U.S. and a credit card issued by a U.S. bank, Amazon Instant Downloads offers episodes from seasons 1 through 4 for download.
 
iTunes
The U.S. store of iTunes offers downloads of season 4.
The quality is much better than in TV airings, but varies from episode to episode. No picture remastering was applied so the picture quality is not as good as the season 3 DVD release.
Only 13 episodes contain the teasers before the main title. The episodes themselves are unedited though.